What is Energy? Energy is the capacity to do work

Size: px
Start display at page:

Download "What is Energy? Energy is the capacity to do work"

Transcription

1 What is Energy? Energy is the capacity to do work

2 Work the product of force exerted on an object and the distance the object moves in the direction of the force. W=Fd W = work (Joules, J) F = force (N) d = displacement (m)

3 Work (cont d) If a large force is applied with no movement, then no work is done. If a force is exerted perpendicular to the motion, then no work is done. If a force is exerted at an angle to the motion, then the force can be replaced by its components. Only the component in the direction of motion does work.

4 Ex. 1 How much work do you do when you climb a 3.0 m high staircase? (Assume your weight is 600 N) F g = 600 N d = 3.0m

5 Ex 2. A man pulls a toboggan along the snow with the rope at an angle of 40.0 with the horizontal. How much work is done by the man if he exerts a force of 255 N on the rope and pulls the toboggan 30.0 m? F = 255N 40.0 o

6 Power rate at which work is done. P = W t P = power, watts (w) W = work, Joules (J) t = time, seconds (s)

7 Ex. 1 How much power is developed by a 70 kg boy running up a flight of stairs, 4.5 m high in a time of 2.5 s? F g d

8 Ex. 2 How much energy (or work!) does a 1500 W toaster convert to heat in 2 minutes?

9 Energy the ability to do work transfer of energy = work done on an object ΔE = W

10 Kinetic Energy Forms of Energy Due to the motion of an object i.e., moving car Potential Energy Stored energy as a result of an object s position. i.e., roller coaster at the top of a hill.

11 Kinetic Energy Result of work being done on an object. Depends on an object s mass and velocity. W = F d and F = ma W = ma d = m ad v f 2 = v i 2 + 2ad OR ad = v f 2 v i 2 2 E k = ½ mv 2 If an object starts at rest, ad = v f2 / 2 W = mv f 2 2

12 Ex. What is the kinetic energy of a 25.0 g bullet traveling at 3600 km/h?

13 Work-Energy Theorem W = E Kf - E Ki = ΔE K The net work done on an object is equal to its change in Kinetic Energy. Net work is positive if net force acts in the same direction as the motion, and kinetic energy increases. Net work is negative if force acts in the opposite direction of the motion, and kinetic energy decreases.

14 Ex#1: How much work does a pitcher do when he accelerates a 145g baseball from rest to 25 m/s?

15 Ex#2: A car gains 577 KJ of kinetic energy when it accelerates from 12 m/s to 25 m/s in 12 seconds. What is the mass of the car?

16 Gravitational Potential Energy Dependent on the object s position above the Earth s surface. since W = F.d F g = mg E p = objects potential energy (J) m = objects mass (kg) g = acceleration due to gravity (9.80 m/s 2 ) h = vertical distance (m) and let d = h then, E p = mgh formula is valid only where g is constant. select a position at which an object s potential energy is zero (lowest point) potential energy is measured relative to the zero point.

17 Ex.#1 Each step on a ladder increases one s vertical height by 40cm. If a 90.0 kg painter climbs eight steps of the ladder, what is the increase in potential energy?

18 Ex. 2 A 10.0 kg rock is on top of a house 3.00 m high on the edge of a cliff that is 20.0 m high. What is the gravitational energy of the rock A) relative to the roof of the house? B) relative to the floor of the house? C) relative to the bottom of the cliff?

19 Conservation of Energy Within a closed, isolated system, energy can change form, but the total amount of energy is constant. Energy can be neither created nor destroyed. Mathematically: E Ki + E Pi = E Kf + E pf Total energy before = Total energy after

20 The decrease in potential energy is equal to the increase in its kinetic energy. ΔE k = ΔE p The total energy, E, of an object is the sum of the kinetic energy and potential energy E = E k + E p

21 Ex. #1 A 20.0 kg rock falls 50 m from rest. a) What is the rock s loss in gravitational energy? b) What is its gain in kinetic energy? c) What is the final speed of the rock?

22 Ex. 2 A girl on a bicycle is on the top of a 15 m high hill. How fast will she be moving at the bottom of the hill? (Ignore friction)

23 Thermal Energy Thermodynamics the study of heat Kinetic Molecular Theory all matter is made up of particles in constant motion. a hotter body has faster moving particles than a cooler body, thus more energy.

24 External Energy of a Baseball result of position and motion of a baseball. E p = mgh E k = ½ mv 2 v h

25 Internal Energy of a Baseball result of the E k and E p of the particles E k of particles = particles vibrate back and forth. E p of particles = position of particles due to electromagnetic forces. Thermal Energy - the sum of the E k and E p energy of the internal motion of particles that make up an object.

26 Thermal Energy Transfer conduction - transfer of kinetic energy in solids when particles of an object collide. convection - heat transfer by the movement of fluids caused by their different densities. radiation - transfer of thermal energy through space in the form of electromagnetic waves (i.e., infrared)

27 Thermal Energy vs. Temperature Thermal Energy the total kinetic energy of all the particles of an object Temperature - the average kinetic energy of the particles of an object; measured with a thermometer. particles of an object have a range of energies, some high and some low. hotter objects have greater average E k of particles.

28 HEAT Heat the amount of thermal energy transferred from one object to another, due to differences in temperatures between the objects Equilibrium occurs when the rate of energy transfer between 2 bodies is equal; objects at equilibrium are at the same temperature

29 Temperature Scales Thermometer - device used to measure temperature. It is placed in contact with an object and allowed to come to thermal equilibrium. Celsius scale based on the properties of water.

30 Kelvin scale based on absolute zero, no upper limit. used to accommodate wide range of temperatures in the universe. absolute zero temperature at which all thermal energy is removed from objects. ( C)

31 Heat energy that flows as a result of a difference in temperature (Q). energy transferred as a result of a difference in temperature. dependent on: a) mass of the object, b) change in temperature, c) specific heat capacity of material.

32 Q = m C ΔT Q = heat energy gained or lost (J) (sometimes E h ) m = mass (kg) C = specific heat (J/Kg o C or J/Kg.K) ΔT = change in temperature ( o C or K)

33 Ex#1. A 0.4 kg block of iron is heated from 295 K to 325 K. How much heat is absorbed by the iron? (Refer to Pg. 160 in workbook for C values)

34 Ex#2. After 250 kj of heat is transferred to a container of water, the temperature rose to from 15 o C to 25 o C. What was the mass of the water in the container?

35 Efficiency Law of Conservation of Energy: the amount of energy present before an energy transformation is equal to the amount of energy present after the transformation. However, some of the energy in a transformation is not a useful form of energy and is wasted.

36 Efficiency = Energy output x 100 Energy input Efficiency - the ability of a device to convert energy Energy output useful energy produced by a converter (J) Energy input energy consumed by the converter (J) Converter Input energy Output energy Car engine Chemical Mechanical (gasoline) (motion)

37 Ex#1: An internal combustion engine burns 1200J of chemical energy. The fuel is vaporized, producing very high temperatures and pressures that push down on the pistons which turn the crankshaft, thus turning the wheels. 100 J of mechanical energy is used to move the car forward. What is the efficiency of the car?

38 Ex#2: A 1200 W electric kettle is used for 10 minutes. a) how much energy does it require? b) If 6.0x10 5 J of energy is transferred to the water in the kettle, what is its efficiency?

Efficiency = power out x 100% power in

Efficiency = power out x 100% power in Work, Energy and Power Review Package 1) Work: change in energy. Measured in Joules, J. W = Fd W = ΔE Work is scalar, but can be negative. To remember this, ask yourself either: Is the object is losing

More information

Physical Science midterm study guide. Chapter 1 and 2

Physical Science midterm study guide. Chapter 1 and 2 Physical Science midterm study guide Chapter 1 and 2 1. Explain the difference between a scientific law and a scientific theory a. Laws generalize observations b. Theories explain observations 2. Select

More information

KINETIC AND POTENTIAL ENERGY. Chapter 6 (cont.)

KINETIC AND POTENTIAL ENERGY. Chapter 6 (cont.) KINETIC AND POTENTIAL ENERGY Chapter 6 (cont.) The Two Types of Mechanical Energy Energy- the ability to do work- measured in joules Potential Energy- energy that arises because of an object s position

More information

Work Done by a Constant Force

Work Done by a Constant Force Work and Energy Work Done by a Constant Force In physics, work is described by what is accomplished when a force acts on an object, and the object moves through a distance. The work done by a constant

More information

Work changes Energy. Do Work Son!

Work changes Energy. Do Work Son! 1 Work changes Energy Do Work Son! 2 Do Work Son! 3 Work Energy Relationship 2 types of energy kinetic : energy of an object in motion potential: stored energy due to position or stored in a spring Work

More information

8.5 - Energy. Energy The property of an object or system that enables it to do work. Energy is measured in Joules (J).

8.5 - Energy. Energy The property of an object or system that enables it to do work. Energy is measured in Joules (J). Work Work The process of moving an object by applying a force. Work = Force x displacement. Work is measured in Joules (J) or Newton-meters (Nm). W = Fd Example: To prove his strength, a weightlifter pushes

More information

Conservation of Energy and Momentum

Conservation of Energy and Momentum Conservation of Energy and Momentum Three criteria for Work There must be a force. There must be a displacement, d. The force must have a component parallel to the displacement. Work, W = F x d, W = Fd

More information

Essentially, the amount of work accomplished can be determined two ways:

Essentially, the amount of work accomplished can be determined two ways: 1 Work and Energy Work is done on an object that can exert a resisting force and is only accomplished if that object will move. In particular, we can describe work done by a specific object (where a force

More information

Chapter 10-Work, Energy & Power

Chapter 10-Work, Energy & Power DULLES HIGH SCHOOL Chapter 10-Work, Energy & Power Energy Transformations Judy Matney 1/12/2016 In this chapter, we will study the concepts of force and work; we will understand the transformations of

More information

Chapter 9 Conceptual Physics Study Guide

Chapter 9 Conceptual Physics Study Guide Name : Date: Period: Chapter 9 Conceptual Physics Study Guide Multiple Choice Identify the choice that best completes the statement or answers the question. 1. In physics, work is defined as a. force times

More information

Preparing for Six Flags Physics Concepts

Preparing for Six Flags Physics Concepts Preparing for Six Flags Physics Concepts uniform means constant, unchanging At a uniform speed, the distance traveled is given by Distance = speed x time At uniform velocity, the displacement is given

More information

Ch 11 ENERGY and its CONSERVATION. work causes a change in the energy of a system KE (an increase or decrease in KE) ket.

Ch 11 ENERGY and its CONSERVATION. work causes a change in the energy of a system KE (an increase or decrease in KE) ket. Ch 11 ENERGY and its CONSERVATION 11.1 The Many Forms of Energy work causes a change in the energy of a system W = KE (an increase or decrease in KE) work energy theorem object + work object work increase

More information

The relationship between force and distance has a name. WORK

The relationship between force and distance has a name. WORK EWP The relationship between force and distance has a name. WORK WORK - the product of the net force and distance through which an object moves in the direction of the net force. W=F d where W=work joules

More information

Section 1: Work, Power, and Machines. Preview Key Ideas Bellringer What Is Work? Math Skills Power Machines and Mechanical Advantage

Section 1: Work, Power, and Machines. Preview Key Ideas Bellringer What Is Work? Math Skills Power Machines and Mechanical Advantage Section 1 Section 1: Work, Power, and Machines Preview Key Ideas Bellringer What Is Work? Math Skills Power Machines and Mechanical Advantage Section 1 Key Ideas How is work calculated? What is the relationship

More information

Mechanics & Properties of Matter 5: Energy and Power

Mechanics & Properties of Matter 5: Energy and Power Mechanics & Properties of Matter 5: Energy and Power Energy and Power AIM This unit re-introduces the formulae for calculating work done, potential energy, kinetic energy and power. The principle that

More information

Phys101 Lectures 9 and 10 Conservation of Mechanical Energy

Phys101 Lectures 9 and 10 Conservation of Mechanical Energy Phys101 Lectures 9 and 10 Conservation of Mechanical Energy Key points: Conservative and Nonconservative Forces Potential Energy Generalized work-energy principle Mechanical Energy and Its Conservation

More information

Phys101 Lectures 9 and 10 Conservation of Mechanical Energy

Phys101 Lectures 9 and 10 Conservation of Mechanical Energy Phys101 Lectures 9 and 10 Conservation of Mechanical Energy Key points: Conservative and Nonconservative Forces Potential Energy Generalized work-energy principle Mechanical Energy and Its Conservation

More information

FORCES AND MOTION UNIT TEST. Multiple Choice: Draw a Circle Completely around the ONE BEST answer.

FORCES AND MOTION UNIT TEST. Multiple Choice: Draw a Circle Completely around the ONE BEST answer. Name: Date: Period: FORCES AND MOTION UNIT TEST Multiple Choice: Draw a Circle Completely around the ONE BEST answer. 1. A force acting on an object does no work if a. a machine is used to move the object.

More information

WORK, POWER & ENERGY

WORK, POWER & ENERGY WORK, POWER & ENERGY Work An applied force acting over a displacement. The force being applied must be parallel to the displacement for work to be occurring. Work Force displacement Units: Newton meter

More information

Physics 101: Lecture 9 Work and Kinetic Energy

Physics 101: Lecture 9 Work and Kinetic Energy Exam II Physics 101: Lecture 9 Work and Kinetic Energy Today s lecture will be on Textbook Sections 6.1-6.4 Physics 101: Lecture 9, Pg 1 Forms Energy Kinetic Energy Motion (Today) Potential Energy Stored

More information

Chapter 3: Force, Work and Energy

Chapter 3: Force, Work and Energy Chapter 3: Force and Force Equilibrium Chapter 3: Force, Work and Energy Chapter 3: Force, Work and Energy 3.1 Mass and Weight 3.2 Newton's Law of Gravitation 3.3 Force and Newton's 3 Laws of Motion 3.4

More information

The Story of Energy. Forms and Functions

The Story of Energy. Forms and Functions The Story of Energy Forms and Functions What are 5 things E helps us do? Batteries store energy! This car uses a lot of energy Even this sleeping puppy is using stored energy. We get our energy from FOOD!

More information

Lecture 5. Work Energy

Lecture 5. Work Energy Lecture 5 Work Energy Work, Energy Work and energy are fundamental physical quantities in science. Work is done when a force moves an object through a distance. Energy is the ability to do work The unit

More information

CHAPTER 13.3 AND 13.4 ENERGY

CHAPTER 13.3 AND 13.4 ENERGY CHAPTER 13.3 AND 13.4 ENERGY Section 13.3 Energy Objective 1: What is the relationship between energy and work? Objective 2: Identify the energy of position. Objective 3: The factors that kinetic energy

More information

In an avalanche, a mass of loose snow, soil, or rock suddenly gives way and slides down the side of a mountain.

In an avalanche, a mass of loose snow, soil, or rock suddenly gives way and slides down the side of a mountain. ENERGY Energy Objective 1: What is the relationship between energy and work? Objective 2: Identify the energy of position. Objective 3: The factors that kinetic energy depends on Objective 4: What is non-mechanical

More information

2 possibilities. 2.) Work is done and... 1.) Work is done and... *** The function of work is to change energy ***

2 possibilities. 2.) Work is done and... 1.) Work is done and... *** The function of work is to change energy *** Work-Energy Theorem and Energy Conservation *** The function of work is to change energy *** 2 possibilities 1.) Work is done and... or 2.) Work is done and... 1 EX: A 100 N box is 10 m above the ground

More information

3. According to the Law of Conservation of Energy, the total amount of energy in the universe

3. According to the Law of Conservation of Energy, the total amount of energy in the universe Directions: Please choose the best answer choice for each of the following questions. 1. Heating an object excites the surface molecules, causing them to give off infrared rays. is the transmission of

More information

Chapter 4. Energy. Work Power Kinetic Energy Potential Energy Conservation of Energy. W = Fs Work = (force)(distance)

Chapter 4. Energy. Work Power Kinetic Energy Potential Energy Conservation of Energy. W = Fs Work = (force)(distance) Chapter 4 Energy In This Chapter: Work Kinetic Energy Potential Energy Conservation of Energy Work Work is a measure of the amount of change (in a general sense) that a force produces when it acts on a

More information

(A) 10 m (B) 20 m (C) 25 m (D) 30 m (E) 40 m

(A) 10 m (B) 20 m (C) 25 m (D) 30 m (E) 40 m Work/nergy 1. student throws a ball upward where the initial potential energy is 0. t a height of 15 meters the ball has a potential energy of 60 joules and is moving upward with a kinetic energy of 40

More information

Physical Science (SCI101) Final Exam

Physical Science (SCI101) Final Exam Department of Mathematics and General Sciences Final Exam Second Semester, Term 132 Date: Wednesday 28/5/2014 Name: ID number: Section number or time: Instructor s name: Important instructions: 1. Examination

More information

Chapter 6 Energy and Oscillations

Chapter 6 Energy and Oscillations Chapter 6 Energy and Oscillations Conservation of Energy In this chapter we will discuss one of the most important and fundamental principles in the universe. Energy is conserved. This means that in any

More information

Physics 231. Topic 5: Energy and Work. Alex Brown October 2, MSU Physics 231 Fall

Physics 231. Topic 5: Energy and Work. Alex Brown October 2, MSU Physics 231 Fall Physics 231 Topic 5: Energy and Work Alex Brown October 2, 2015 MSU Physics 231 Fall 2015 1 What s up? (Friday Sept 26) 1) The correction exam is now open. The exam grades will be sent out after that on

More information

Work and Energy Energy Conservation

Work and Energy Energy Conservation Work and Energy Energy Conservation MidterM 1 statistics Mean = 16.48 Average = 2.74 2 Clicker Question #5 Rocket Science!!! The major principle of rocket propulsion is: a) Conservation of energy b) Conservation

More information

Work, Power and Energy Worksheet. 2. Calculate the work done by a 47 N force pushing a kg pencil 0.25 m against a force of 23 N.

Work, Power and Energy Worksheet. 2. Calculate the work done by a 47 N force pushing a kg pencil 0.25 m against a force of 23 N. Work, Power and Energy Worksheet Work and Power 1. Calculate the work done by a 47 N force pushing a pencil 0.26 m. 2. Calculate the work done by a 47 N force pushing a 0.025 kg pencil 0.25 m against a

More information

Power: Sources of Energy

Power: Sources of Energy Chapter 5 Energy Power: Sources of Energy Tidal Power SF Bay Tidal Power Project Main Ideas (Encyclopedia of Physics) Energy is an abstract quantity that an object is said to possess. It is not something

More information

Physics Unit 4:Work & Energy Name:

Physics Unit 4:Work & Energy Name: Name: Review and Preview We have come a long way in our study of mechanics. We started with the concepts of displacement and time, and built up to the more complex quantities of velocity and acceleration.

More information

Kinetic and Potential Energy. Supplemental Text Material Pages

Kinetic and Potential Energy. Supplemental Text Material Pages Kinetic and Potential Energy Supplemental Text Material Pages 326-333 Work Transference of Energy Work = Force x distance W=Fd Work Lifting load against the force of the weight of the object Twice the

More information

AQA Physics P2 Topic 1. Motion

AQA Physics P2 Topic 1. Motion AQA Physics P2 Topic 1 Motion Distance / Time graphs Horizontal lines mean the object is stationary. Straight sloping lines mean the object is travelling at a constant speed. The steeper the slope, the

More information

AP PHYSICS 1. Energy 2016 EDITION

AP PHYSICS 1. Energy 2016 EDITION AP PHYSICS 1 Energy 2016 EDITION Copyright 2016 National Math + Initiative, Dallas, Texas. All rights reserved. Visit us online at www.nms.org. 1 Pre-Assessment Questions Consider a system which could

More information

ENERGY. Unit 12: IPC

ENERGY. Unit 12: IPC ENERGY Unit 12: IPC WHAT IS ENERGY? Energy- is the ability to do work. Energy is the ability to cause a change. Energy can change an object s: motion shape temperature color THERMAL internal motion of

More information

UNIT 5: WORK and ENERGY RECORD ALL ANSWERS ON ANSWER SHEET.

UNIT 5: WORK and ENERGY RECORD ALL ANSWERS ON ANSWER SHEET. PHYSICAL SCIENCE UNIT 5: WORK and ENERGY RECORD ALL ANSWERS ON ANSWER SHEET. name 1. Which of the following processes requires the most work? a. A 10 kg weight rests on a table. b. A person holds a 1 kg

More information

Work Work has a variety of meanings (taking out the trash is hard work; the toaster doesn t work; Mom goes to work)

Work Work has a variety of meanings (taking out the trash is hard work; the toaster doesn t work; Mom goes to work) Physics Work, Power, and Energy Notes (Chapter 8 in Textbook) Key Terms Work Power Energy Potential Kinetic Mechanical Energy Law of Conservation of Energy Work-Energy Theorem Joule Watt Work Work has

More information

NCERT solution for Work and energy

NCERT solution for Work and energy 1 NCERT solution for Work and energy Question 1 A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (See below figure). Let us take it that the force acts on the

More information

Chapter 6 Work and Energy

Chapter 6 Work and Energy Chapter 6 Work and Energy Units of Chapter 6 Work Done by a Constant Force Work Done by a Varying Force Kinetic Energy, and the Work-Energy Principle Potential Energy Conservative and Nonconservative Forces

More information

Mechanical Energy Thermal Energy Chemical Energy Electrical Energy Electromagnetic Energy

Mechanical Energy Thermal Energy Chemical Energy Electrical Energy Electromagnetic Energy Physical Science PHYSICS UNIT 4 Study Guide. Chapter 15 - Energy Key Terms Energy Kinetic Energy Potential Gravitational Potential Elastic Potential Mechanical Energy Thermal Energy Chemical Energy Electrical

More information

Broughton High School of Wake County

Broughton High School of Wake County Physical Science Vocabulary Vocabulary for Chapter 4 No.# Term Page # Mechanical Energy Elastic Potential Energy Joule Potential Energy Definition Kinetic Energy Formula Law of Conservation of energy Chemical

More information

Class IX Chapter 11 Work and Energy Science

Class IX Chapter 11 Work and Energy Science Class IX Chapter 11 Work and Energy Science Question 1: A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (Fig. 11.3). Let us take it that the force acts on

More information

Copyright 2014 Edmentum - All rights reserved.

Copyright 2014 Edmentum - All rights reserved. Copyright 2014 Edmentum - All rights reserved. Science Physics Energy and Power Blizzard Bag 2014-2015 1. A woman wants to lift a 10.0-kg rock from the ground to a height of 8.0 m. What is the minimum

More information

Pre Comp Review Questions 7 th Grade

Pre Comp Review Questions 7 th Grade Pre Comp Review Questions 7 th Grade Section 1 Units 1. Fill in the missing SI and English Units Measurement SI Unit SI Symbol English Unit English Symbol Time second s second s. Temperature Kelvin K Fahrenheit

More information

Work. Work is the measure of energy transferred. Energy: the capacity to do work. W = F X d

Work. Work is the measure of energy transferred. Energy: the capacity to do work. W = F X d ENERGY CHAPTER 11 Work Work is the measure of energy transferred. Energy: the capacity to do work. W = F X d Units = Joules Work and energy transferred are equivalent in ideal systems. Two Types of Energy

More information

Potential Energy & Conservation of Energy Physics

Potential Energy & Conservation of Energy Physics Potential Energy & Conservation of Energy Physics Work and Change in Energy If we rearrange the Work-Kinetic Energy theorem as follows Ki +Fcosφ d = Kf => Fcosφ d = Kf - Ki => Fcosφ d = K => Ki + ΣΣW =

More information

Chapter 6 Work, Energy, and Power. Copyright 2010 Pearson Education, Inc.

Chapter 6 Work, Energy, and Power. Copyright 2010 Pearson Education, Inc. Chapter 6 Work, Energy, and Power What Is Physics All About? Matter Energy Force Work Done by a Constant Force The definition of work, when the force is parallel to the displacement: W = Fs SI unit: newton-meter

More information

CHAPTER 6: IN AN ISOLATED SYSTEM, ENERGY IS TRANSFERRED FROM ONE OBJECT TO ANOTHER WHENEVER WORK IS DONE

CHAPTER 6: IN AN ISOLATED SYSTEM, ENERGY IS TRANSFERRED FROM ONE OBJECT TO ANOTHER WHENEVER WORK IS DONE CHAPTER 6: IN AN ISOLATED SYSTEM, ENERGY IS TRANSFERRED FROM ONE OBJECT TO ANOTHER WHENEVER WORK IS DONE 6.1 Work and Energy In science, work is done when a force acts over a displacement; energy is transferred.

More information

PSI AP Physics I Work and Energy

PSI AP Physics I Work and Energy PSI AP Physics I Work and Energy Multiple-Choice questions 1. A driver in a 2000 kg Porsche wishes to pass a slow moving school bus on a 4 lane road. What is the average power in watts required to accelerate

More information

23. A snowmobile pulls a trailer with a force of 450 N while moving at a constant velocity of 15 m/s. How much work is done by the snowmobile in 28 s?

23. A snowmobile pulls a trailer with a force of 450 N while moving at a constant velocity of 15 m/s. How much work is done by the snowmobile in 28 s? Physics 04 Unit Review (June 013) 1. Which represents the rate of work done? (A) efficiency (B) force (C) power (D) work. In which situation is work done on a box? (A) The box is at rest on a table. (B)

More information

Work, Power and Energy Worksheet

Work, Power and Energy Worksheet Work, Power and Energy Worksheet Name: 1. Which of the following statements are true about work? Include all that apply. a. Work is the transfer of energy into or out of a system by means of an external

More information

HW and Exam #1. HW#3 Chap. 5 Concept: 22, Problems: 2, 4 Chap. 6 Concept: 18, Problems: 2, 6

HW and Exam #1. HW#3 Chap. 5 Concept: 22, Problems: 2, 4 Chap. 6 Concept: 18, Problems: 2, 6 HW and Exam #1 HW#3 Chap. 5 Concept: 22, Problems: 2, 4 Chap. 6 Concept: 18, Problems: 2, 6 Hour Exam I, Wednesday Sep 29, in-class Material from Chapters 1,3,4,5,6 One page of notes (8.5 x 11 ) allowed

More information

WEP-Work and Power. What is the amount of work done against gravity as an identical mass is moved from A to C? J J J 4.

WEP-Work and Power. What is the amount of work done against gravity as an identical mass is moved from A to C? J J J 4. 1. The work done in accelerating an object along a frictionless horizontal surface is equal to the change in the object s 1. momentum 2. velocity 3. potential energy 4. kinetic energy 2. The graph below

More information

AP Physics 1 Work Energy and Power Practice Test Name

AP Physics 1 Work Energy and Power Practice Test Name AP Physics 1 Work Energy and Power Practice Test Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Two objects, one of mass m and the other

More information

Name. Honors Physics AND POTENTIAL KINETIC

Name. Honors Physics AND POTENTIAL KINETIC KINETIC Name Honors Physics AND POTENTIAL Name Period Work and Energy Intro questions Read chapter 9 pages 144 146 (Section 9.1) 1. Define work in terms of physics? 2. In order to do work on an object,

More information

Work and the Work-Energy Theorem

Work and the Work-Energy Theorem Work and Energy Click on the topic to go to that section Energy and the Work-Energy Theorem Work and Energy 2009 by Goodman & Zavorotniy Forces and Potential Energy Conservation of Energy Power Conservation

More information

W = Fd cos θ. W = (75.0 N)(25.0 m) cos (35.0º) = 1536 J = J. W 2400 kcal =

W = Fd cos θ. W = (75.0 N)(25.0 m) cos (35.0º) = 1536 J = J. W 2400 kcal = 8 CHAPTER 7 WORK, ENERGY, AND ENERGY RESOURCES generator does negative work on the briefcase, thus removing energy from it. The drawing shows the latter, with the force from the generator upward on the

More information

Unit 3 Energy and Society Work and Energy

Unit 3 Energy and Society Work and Energy Unit 3 Energy and Society Work and Energy Today's goal: I can identify energy issues that exist and can articulate the connection between issues and work and energy. Energy Issues: Definitions: Energy

More information

PHYS 101 Previous Exam Problems. Kinetic Energy and

PHYS 101 Previous Exam Problems. Kinetic Energy and PHYS 101 Previous Exam Problems CHAPTER 7 Kinetic Energy and Work Kinetic energy Work Work-energy theorem Gravitational work Work of spring forces Power 1. A single force acts on a 5.0-kg object in such

More information

2013, 2011, 2009, 2008 AP

2013, 2011, 2009, 2008 AP Lecture 15 Thermodynamics I Heat vs. Temperature Enthalpy and Work Endothermic and Exothermic Reactions Average Bond Enthalpy Thermodynamics The relationship between chemical reactions and heat. What causes

More information

Ch 6 Using Newton s Laws. Applications to mass, weight, friction, air resistance, and periodic motion

Ch 6 Using Newton s Laws. Applications to mass, weight, friction, air resistance, and periodic motion Ch 6 Using Newton s Laws Applications to mass, weight, friction, air resistance, and periodic motion Newton s 2 nd Law Applied Galileo hypothesized that all objects gain speed at the same rate (have the

More information

Section 1 Work, Power, and Machines

Section 1 Work, Power, and Machines Chapter 12 Work and Energy Section 1 Work, Power, and Machines Section 2 Simple Machines Section 3 What is Energy? Section 4 Conservation of Energy Skills Experiment Design SI Units and SI unit conversions

More information

Momentum, Impulse, Work, Energy, Power, and Conservation Laws

Momentum, Impulse, Work, Energy, Power, and Conservation Laws Momentum, Impulse, Work, Energy, Power, and Conservation Laws 1. Cart A has a mass of 2 kilograms and a speed of 3 meters per second. Cart B has a mass of 3 kilograms and a speed of 2 meters per second.

More information

Energy "is an abstract concept invented by scientists in the nineteenth century to describe quantitatively a wide variety of natural phenomena.

Energy is an abstract concept invented by scientists in the nineteenth century to describe quantitatively a wide variety of natural phenomena. Energy Energy "is an abstract concept invented by scientists in the nineteenth century to describe quantitatively a wide variety of natural phenomena." David Rose What is energy? Energy makes changes;

More information

P1 Quick Revision Questions. P1 for AQA GCSE examination 2018 onwards

P1 Quick Revision Questions. P1 for AQA GCSE examination 2018 onwards P1 Quick Revision Questions Question 1... of 50 What type of energy is stored in a stretched elastic band? Answer 1... of 50 Elastic potential energy. Question 2... of 50 What type of energy is stored

More information

Work and Energy Definition of work Examples. Definition of Mechanical Energy. Conservation of Mechanical Energy, Pg 1

Work and Energy Definition of work Examples. Definition of Mechanical Energy. Conservation of Mechanical Energy, Pg 1 Work and Energy Definition of work Examples Work and Energy Today s Agenda Definition of Mechanical Energy Conservation of Mechanical Energy Conservative forces Conservation of Mechanical Energy, Pg 1

More information

Work Energy Review. 1. Base your answer to the following question on the information and diagram below and on your knowledge of physics.

Work Energy Review. 1. Base your answer to the following question on the information and diagram below and on your knowledge of physics. Name: ate: 1. ase your answer to the following question on the information and diagram below and on your knowledge of physics. student pushes a box, weighing 50. newtons, 6.0 meters up an incline at a

More information

1. A train moves at a constant velocity of 90 km/h. How far will it move in 0.25 h? A. 10 km B km C. 25 km D. 45 km E. 50 km

1. A train moves at a constant velocity of 90 km/h. How far will it move in 0.25 h? A. 10 km B km C. 25 km D. 45 km E. 50 km Name: Physics I Mid Term Exam Review Multiple Choice Questions Date: Mr. Tiesler 1. A train moves at a constant velocity of 90 km/h. How far will it move in 0.25 h? A. 10 km B. 22.5 km C. 25 km D. 45 km

More information

Chapter 8 Conservation of Energy. Copyright 2009 Pearson Education, Inc.

Chapter 8 Conservation of Energy. Copyright 2009 Pearson Education, Inc. Chapter 8 Conservation of Energy Units of Chapter 8 Conservative and Nonconservative Forces Potential Energy Mechanical Energy and Its Conservation Problem Solving Using Conservation of Mechanical Energy

More information

velocity, force and momentum are vectors, therefore direction matters!!!!!!!

velocity, force and momentum are vectors, therefore direction matters!!!!!!! 1 Momentum, p is mass times velocity: p = m v vector! unit: (p) = kg m/s Newton s second law: Force = time rate of change of momentum Net force F will produce change in momentum Δp of the object on which

More information

WEP-Energy. 2. If the speed of a car is doubled, the kinetic energy of the car is 1. quadrupled 2. quartered 3. doubled 4. halved

WEP-Energy. 2. If the speed of a car is doubled, the kinetic energy of the car is 1. quadrupled 2. quartered 3. doubled 4. halved 1. A 1-kilogram rock is dropped from a cliff 90 meters high. After falling 20 meters, the kinetic energy of the rock is approximately 1. 20 J 2. 200 J 3. 700 J 4. 900 J 2. If the speed of a car is doubled,

More information

An Introduction. Work

An Introduction. Work Work and Energy An Introduction Work Work tells us how much a force or combination of forces changes the energy of a system. Work is the bridge between force (a vector) and energy (a scalar). W = F Dr

More information

Unit 2: Energy THERMAL ENERGY HEAT TRANSFER POTENTIAL VS. KINETIC ENERGY WORK POWER SIMPLE MACHINES

Unit 2: Energy THERMAL ENERGY HEAT TRANSFER POTENTIAL VS. KINETIC ENERGY WORK POWER SIMPLE MACHINES Unit 2: Energy THERMAL ENERGY HEAT TRANSFER POTENTIAL VS. KINETIC ENERGY WORK POWER SIMPLE MACHINES Bellringer Day 01 1. What is energy? 2. There are different forms of energy. Name two. What is Energy?

More information

Homework #5. Ph 231 Introductory Physics, Sp-03 Page 1 of 4

Homework #5. Ph 231 Introductory Physics, Sp-03 Page 1 of 4 Homework #. Ph Introductory Physics, Sp-0 Page of -A. A 7 kg block moves in a straight line under the influence of a force that varies with position as shown in the figure at the right. If the force is

More information

PH7_UnitPacketCompleteKey

PH7_UnitPacketCompleteKey Page 1 of 45 Page 2 of 45 Unit Packet Contents 1. Unit Objectives 2. Notes: Potential / Kinetic Energy 3. Guided Practice: Potential and Kinetic Energy 4. Independent Practice Potential and Kinetic Energy

More information

Ch06. Energy. Thermochemistry, understanding energy, heat & work. version 1.5

Ch06. Energy. Thermochemistry, understanding energy, heat & work. version 1.5 Ch06 Energy Thermochemistry, understanding energy, heat & work. version 1.5 Nick DeMello, PhD. 2007-2016 Ch06 Accounting for Energy Energy Definitions Classifications Units Kinetic, Potential, Thermal

More information

Name 09-MAR-04. Work Power and Energy

Name 09-MAR-04. Work Power and Energy Page 1 of 16 Work Power and Energy Name 09-MAR-04 1. A spring has a spring constant of 120 newtons/meter. How much potential energy is stored in the spring as it is stretched 0.20 meter? 1. 2.4 J 3. 12

More information

Important: This test consists of 15 multiple choice problems, each worth points.

Important: This test consists of 15 multiple choice problems, each worth points. Physics 214 Practice Exam 1 C Fill in on the OPSCAN sheet: 1) Name 2) Student identification number 3) Exam number as 01 4) Sign the OPSCAN sheet Important: This test consists of 15 multiple choice problems,

More information

Momentum and Energy. Chapter 3

Momentum and Energy. Chapter 3 Momentum and Energy Chapter 3 Momentum Momentum is inertia in motion Mass x velocity Has both magnitude and direction Large mass or high speed can give object great amount of momentum Momentum = m v Change

More information

Chapters 10 & 11: Energy

Chapters 10 & 11: Energy Chapters 10 & 11: Energy Power: Sources of Energy Tidal Power SF Bay Tidal Power Project Main Ideas (Encyclopedia of Physics) Energy is an abstract quantity that an object is said to possess. It is not

More information

1 1. A spring has a spring constant of 120 newtons/meter. How much potential energy is stored in the spring as it is stretched 0.20 meter?

1 1. A spring has a spring constant of 120 newtons/meter. How much potential energy is stored in the spring as it is stretched 0.20 meter? Page of 3 Work Power And Energy TEACHER ANSWER KEY March 09, 200. A spring has a spring constant of 20 newtons/meter. How much potential energy is stored in the spring as it is stretched 0.20 meter?. 2.

More information

Physics Year 11 Term 1 Week 7

Physics Year 11 Term 1 Week 7 Physics Year 11 Term 1 Week 7 Energy According to Einstein, a counterpart to mass An enormously important but abstract concept Energy can be stored (coal, oil, a watch spring) Energy is something moving

More information

Work and Energy. Intext Exercise 2

Work and Energy. Intext Exercise 2 Intext Exercise 1 Question 1: A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (Fig. 11.3). Let us take it that the force acts on the object through the displacement.

More information

Momentum, Impulse, Work, Energy, Power, and Conservation Laws

Momentum, Impulse, Work, Energy, Power, and Conservation Laws Momentum, Impulse, Work, Energy, Power, and Conservation Laws 1. Cart A has a mass of 2 kilograms and a speed of 3 meters per second. Cart B has a mass of 3 kilograms and a speed of 2 meters per second.

More information

Force. The cause of an acceleration or change in an object s motion. Any kind of a push or pull on an object.

Force. The cause of an acceleration or change in an object s motion. Any kind of a push or pull on an object. Force The cause of an acceleration or change in an object s motion. Any kind of a push or pull on an object. Forces do not always give rise to motion. Forces can be equal and opposite. Force is a vector

More information

Potential Energy & Conservation of Energy

Potential Energy & Conservation of Energy Potential Energy & Conservation of Energy Level : Physics I Teacher : Kim Work and Change in Energy If we rearrange the Work-Kinetic Energy theorem as follows K i +Fcosφ d = K f => Fcosφ d = K f - K i

More information

What is Energy? Which has more energy? Who has more energy? 1/24/2017

What is Energy? Which has more energy? Who has more energy? 1/24/2017 What is Energy? Energy is a measure of an object s ability to cause a change in itself and/or its surroundings Read pages 61-7 Which has more energy? Who has more energy? Mississippi River Cargo Barge

More information

Wiley Plus. Final Assignment (5) Is Due Today: Before 11 pm!

Wiley Plus. Final Assignment (5) Is Due Today: Before 11 pm! Wiley Plus Final Assignment (5) Is Due Today: Before 11 pm! Final Exam Review December 9, 009 3 What about vector subtraction? Suppose you are given the vector relation A B C RULE: The resultant vector

More information

WEP-Energy. 2. If the speed of a car is doubled, the kinetic energy of the car is 1. quadrupled 2. quartered 3. doubled 4. halved

WEP-Energy. 2. If the speed of a car is doubled, the kinetic energy of the car is 1. quadrupled 2. quartered 3. doubled 4. halved 1. A 1-kilogram rock is dropped from a cliff 90 meters high. After falling 20 meters, the kinetic energy of the rock is approximately 1. 20 J 2. 200 J 3. 700 J 4. 900 J 2. If the speed of a car is doubled,

More information

Physics 23 Exam 2 March 3, 2009

Physics 23 Exam 2 March 3, 2009 Use the following to answer question 1: A stationary 4-kg shell explodes into three pieces. Two of the fragments have a mass of 1 kg each and move along the paths shown with a speed of 10 m/s. The third

More information

What does temperature have to do with energy? What three temperature scales are commonly used? What makes things feel hot or cold?

What does temperature have to do with energy? What three temperature scales are commonly used? What makes things feel hot or cold? Heat and Temperature Section 1: Temperature What does temperature have to do with energy? What three temperature scales are commonly used? What makes things feel hot or cold? 1 Intro: Discussion A person

More information

What is Energy? Energy- is the ability to do work. Energy is the ability to cause a change. Energy can change an object s:

What is Energy? Energy- is the ability to do work. Energy is the ability to cause a change. Energy can change an object s: Energy & Work What is Energy? Energy- is the ability to do work. Energy is the ability to cause a change. Energy can change an object s: motion temperature shape color http://www.youtube.com/watch?v=-dpbvtabkju

More information

Mechanics. Time (s) Distance (m) Velocity (m/s) Acceleration (m/s 2 ) = + displacement/time.

Mechanics. Time (s) Distance (m) Velocity (m/s) Acceleration (m/s 2 ) = + displacement/time. Mechanics Symbols: Equations: Kinematics The Study of Motion s = distance or displacement v = final speed or velocity u = initial speed or velocity a = average acceleration s u+ v v v u v= also v= a =

More information

Physics 201, Midterm Exam 2, Fall Answer Key

Physics 201, Midterm Exam 2, Fall Answer Key Physics 201, Midterm Exam 2, Fall 2006 Answer Key 1) A constant force is applied to a body that is already moving. The force is directed at an angle of 60 degrees to the direction of the body s velocity.

More information

Study Guide For Midterm - 25 weeks Physics Exam. d. the force exerted by a towing cable on the car. c. the upward force the road exerts on the car.

Study Guide For Midterm - 25 weeks Physics Exam. d. the force exerted by a towing cable on the car. c. the upward force the road exerts on the car. Name: Class: Date: ID: A Study Guide For Midterm - 25 weeks Physics Exam Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Which of the following is the

More information