North Carolina Essential Standards Assessment Examples Physics

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1 This document is designed to assist North Carolina educators in effective instruction of the new Common Core State and/or North Carolina Essential Standards (Standard Course of Study) in order to increase student achievement. NCDPI staff are continually updating and improving instructional tools to better serve teachers. North Carolina Essential Standards Assessment Examples Physics What is the purpose of this tool? Assessment is a vital component of the teaching and learning process. These assessment examples are aligned to new content standards and reinforce teaching the standards to their intended level of deep mastery. The purpose of providing examples is to illustrate ways in which the standards or part(s) of the standards might be assessed in the classroom. How do I send Feedback? We intend the examples in this document to be helpful and specific. That said, we believe that as this document is used, educators will find ways in which the tool can be improved and made even more useful. Please send feedback to us at feedback@dpi.nc.gov and we will use your input to refine our instructional tool. Thank You! Where are the new Common Core State and North Carolina Essential Standards? All standards are located at

2 Essential Standards Physics Forces and Motion Phy.1.1 Analyze motion of objects. Phy.1.2 Analyze systems of forces and their interaction with matter. Phy.1.3 Analyze the motion of objects based on the principles of conservation of momentum, conservation of energy and impulse. Energy: Conservation & Transfer Phy.2.1 Understand the concepts of work, energy and power, as well as the relationship among them. Phy.2.2 Analyze the behavior of waves. Phy.2.3 Analyze the nature of moving charges and electric circuits. Interactions of Energy and Matter Phy.3.1 Explain charges and electrostatic systems. Phy.3.2 Explain the concept of magnetism. 2 NC Department of Public Instruction

3 Forces and Motion Essential Standards Clarifying Objectives Assessment Examples Phy.1.1 Analyze the motion of objects. Phy Analyze motion graphically and numerically using vectors, graphs and A person in a rowboat attempts to cross a river that flows west with a strong current. The students starts on the south bank of the river and is trying to reach the north bank directly across. In what direction should the student row the boat? a. due north b. due west c. in a northwesterly direction d. in a northeasterly direction The velocity time graph represents the motion of a car traveling over a time interval of 6 seconds. Describe the car s motion including acceleration, velocity and displacement over the 6 second time interval shown. 3 NC Department of Public Instruction

4 1.1.1 A person throws a ball upward into the air. Which represents the motion of the ball just after the ball leaves the person s hand? a. Velocity and acceleration are both upward. b. Velocity and acceleration are both downward. c. Velocity is upward and acceleration is downward. d. Velocity is downward and acceleration is upward. Phy Analyze motion in one dimension using time, distance, displacement, velocity and acceleration The graph represents the relationship between velocity and time for an object. What is the acceleration of the object? a. 15 m/sec/sec b. 5 m/sec/sec c. 3 m/sec/sec d. 0 m/sec/sec A ball is thrown straight up. When the ball reaches the highest point its velocity is zero. Is the acceleration also zero? Explain your answer and include a velocity-time graph sketch in your explanation. 4 NC Department of Public Instruction

5 Phy Analyze motion in two dimensions using angle of trajectory, time, distance, displacement, velocity and acceleration Which object will strike the ground first: one that is thrown horizontally from a cliff or one that is dropped simultaneously from the same height? a. the one that is thrown b. the one that is dropped c. hit at the same time d. cannot be determined Phy.1.2 Analyze systems of forces and their interaction with matter. Phy Analyze forces and systems of forces graphically and numerically using vectors, graphs and An object is thrown off a cliff above level ground with an initial horizontal velocity of 15 m/s. It takes 4 seconds for the object to reach the ground. If air resistance is negligible, what is the height of the cliff? a. 60 m b. 80 m c. 120 m d. 160 m Support your answer with an explanation and A spring launcher is set on the edge of a laboratory table. A ball is launched with a horizontal velocity v 1 and falls to the floor a horizontal distance d 1 from the table. A second ball is launched from the spring with a velocity three times that of v i. How does the horizontal distance d 2 of the second ball compare to d 1 of the first ball? a. d 2 =d 1 b. d 2 =d 1 /3 c. d 2 =1.73d 1 d. d 2 =3d Determine the net force on the object due to concurrent forces of 25 N North and 10 N East. Explain your 5 NC Department of Public Instruction

6 Phy Analyze systems of forces in one dimension and two dimensions using free body diagrams A football is kicked at an angle of 40 degrees above the horizontal with a force of 5.0 N. (a) Draw a free body diagram for the ball before, during and after contact. (b) Determine the horizontal and vertical components of the force. Explain your Draw free-body diagrams for the following examples and label the forces. Examples: (a) Box sliding down an incline plane, (b) a person pushing a lawn mower, (c) two boxes attached to a pulley with box 1 resting and box 2 hanging from the pulley (Atwood Machine). Explain your diagrams. Phy Explain forces using Newton s laws of motion as well as the universal law of gravitation Two students are pushing a stalled car. What is the acceleration of the car? a m/s/s b m/s/s c m/s/s d m/s/s The gravitational force between two masses is 1.0 x 10 3 N. If the distance between the masses is doubled, what gravitational force would exist? a. 2.0 x 10 3 N b. 5.0 x 10 2 N c. 2.5 x 10 2 N d. 1.0 x 10 2 N 6 NC Department of Public Instruction

7 Phy Explain the effects of forces (including weight, normal, tension, and friction) on objects A force F A pulls on a box with a mass of m on a rough surface. W represents the weight of the box. F N represents the normal force on the box, and F fr represents the frictional force. Describe the relationship between the forces when the box moves with (a) constant velocity, and (b) constant acceleration A block of mass M is motionless on a frictionless inclined plane. The mass is attached to the wall with a string. What represents the magnitude of the tension T in the string? a. Mg sin b. Mg tan c. Mg cos d. Zero Newtons 7 NC Department of Public Instruction

8 Phy Analyze basic forces related to rotation in a circular path (centripetal force) A person swings a stone attached to a string in a circle over her head. The string makes one complete revolution every second. The tension in the string is F T. She increases the speed of the moving stone, without changing the radius of the circle and the string makes two revolutions every second. What is the effect on the tension of the string? a. The tension is unchanged b. The tension decreases to half the original value c. The tension increases to twice the original value d. The tension increases to four times the original value Phy.1.3 Analyze the motion of objects based on the principles of conservation of momentum, conservation of energy and impulse. Phy Analyze the motion of objects involved in completely elastic and completely inelastic collisions by using the principles of conservation of momentum and conservation of energy Explain how centripetal acceleration occurs when an automobile rounds a curve A 62 kg skater is skating due west at 3.0 m/s when she collides with a 42 kg skater headed east at 12 m/s. If they remain tangled together, what is their final velocity? A 40 kg physics student is riding a 1.5 kg skateboard. He is traveling 2.8 m/s. The student jumps off of the skateboard and the skateboard immediately stops. What is the speed and direction of the student s jump? a. 2.8 m/s in the opposite direction as he was riding b. 2.8 m/s in the same direction as he was riding c. 2.9 m/s in the opposite direction as he was riding d. 2.9 m/s in the same direction as he was riding A 60-kg student on ice skates stands at rest on a frictionless frozen pond and holds a 10-kg brick. He throws the brick east with a speed of 18 m/s. What is the resulting velocity of the student? a. 3.0 m/s west b. 3.0 m/s east c. 18 m/s west d. 18 m/s east 8 NC Department of Public Instruction

9 1.3.1 Explain why inelastic collisions do not break the law of conservation of energy. What is meant by conserved in a system of objects? Phy Analyze the motion of objects based on the relationship between momentum and impulse A 15.0 kg object, moving at 11 m/s, crashes into a wall and is stopped in s. a. Determine the impulse and stopping force on the object. b. How would increasing the stopping time affect the impulse and force on the object? A 2.0 x 10 2 g mass slides across a frictionless surface with a velocity of 41 m/s. It hits a wall and bounces back in the opposite direction at 22 m/s. If the collision takes 4.0 x 10-4 s to occur, what force is applied by the wall on the mass? a x 10 3 N b x 10 4 N c x 10 6 N d x 10 7 N 9 NC Department of Public Instruction

10 Energy: Conservation and Transfer Essential Standards Clarifying Objectives Assessment Examples Phy.2.1 Understand the concepts of work, energy and power, as well as the relationship among them. Phy Interpret data on work and energy presented graphically and numerically A horizontal force, F, is used to pull a 5.0-kg block across a floor at a constant speed of 3.0 m/s. The frictional force between the block and the floor is 10 N. The work done by the force in 1 minute is most nearly a. 0 J b. 30 J c. 600 J d. 1,800 J A force moves an object in the direction of the force. Using the force versus position graph shown, determine the work done when the object moves from 2.0 m to 4.0 m. Explain your reasoning and 10 NC Department of Public Instruction

11 Phy Compare the concepts of potential and kinetic energy and conservation of total mechanical energy in the description of motion of objects The diagram below shows a rock on the edge of cliff where h is the height of the cliff. h If the rock rolls off the cliff, what is the kinetic energy of the rock just before it hits the ground? a. mgh b. 1 2 m 0 2 c. 1 2 m 0 mgh 2 d. mgh 1 2 m A 58-kilogram pole vaulter needs to vault a height of 6.0 m. Assuming that all his kinetic energy can be used for the vault, what is the speed that the vaulter must be traveling in order to clear this height? Ignore elastic PE of the bent pole. a. 9.8 m/s b. 15 m/s c. 11 m/s d. 36 m/s 11 NC Department of Public Instruction

12 Phy Explain the relationship among work, power and energy Which is a correct statement about the relationship between work, energy and power? a. Work transfers energy. Power is the rate at which work is done or energy transferred. b. Work is only done when an object is moved. Energy and power are the same quantity. c. Power is measure of how much work can be done. Energy is a measure of the time interval in which the work is done. d. Energy and power are a measure of the amount of force while work is related only to the distance an object moves. Phy.2.2 Analyze the behavior of waves. Phy Analyze how energy is transmitted through waves, using the fundamental characteristics of waves: wavelength, period, frequency, amplitude, and wave velocity. Phy Analyze wave behaviors in terms of transmission, reflection, refraction and interference Is there a difference between the velocity of a wave moving along a string and the velocity of a particle of the string? Explain your answer A sound wave of 410Hz travels through air at 335 m/s. (a) Determine the wavelength. (b) If the frequency doubled, what would be the resulting wavelength and wave speed? (c) What characteristic of the wave is a measure of energy transmitted? Explain your answers and reasoning for How will a ray of light be affected as it passes from air into water? a. Its frequency and wavelength will increase. b. Its frequency and wavelength will decrease. c. Its frequency and unchanged but its wavelength increases. d. Its frequency is unchanged but its wavelength decreases Draw wave pulses that demonstrate destructive and constructive interference. Explain these sketches by discussing wave displacement, direction, and amplitude. Phy Compare mechanical and electromagnetic waves in terms of wave characteristics and behavior What will most likely happen when a ringing bell is placed inside a bell jar connected to a vacuum pump? 12 NC Department of Public Instruction

13 (specifically sound and light). a. The sound intensity of the bell will increase. b. The sound intensity of the bell will decrease. c. The frequency of the sound will increase. d. The speed of the sound will increase Compare sound and light waves in terms of the following: (a) how they are produced, (b) wave speed, (c) interference. Phy.2.3 Analyze the nature of moving charges and electric circuits. Phy Explain Ohm s law in relation to electric circuits If the amount of charge that flows through a circuit depends on how much the metal wire resists the flow of charge, describe the mathematical relationship between current and resistance Why would a current exist in an electric circuit? a. because the electrons collide with other particles in the conductor b. because the electrons collide with other particles in the insulator c. because an electric potential difference exists across the ends of the circuits d. because the amount of charge is reduced on the electrons Use the diagram below to answer the question that follows. In the circuit shown, a voltage of 6 V pushes charge through two resistors of 3Ω each. What is the current in the circuit? 13 NC Department of Public Instruction

14 a. 1 A b. 2 A c. 3 A d. 6 A Support your answer with an explanation and reasoning for Phy Differentiate the behavior of moving charges in conductors and insulators Which is least likely to affect the resistance of an electric circuit? a. the length of the wire b. the insulator on the wire c. the cross-section of the wire d. the resistivity of the wire In a good insulator, what is most likely true of electrons? a. They are free to move around. b. They are held close to the nucleus. c. They move from the conductor to the insulator. d. They move from the insulator to the conductor. Phy Compare the general characteristics of AC and DC systems without How are AC and DC current different? a. Alternating current produces a flow of protons, while direct current produces a flow of electrons. b. Alternating current steadily flows in one direction, while direct current flows in two directions. c. Direct current is produced by an electric generator, while alternating current is produced by a battery. d. Direct current flows in one direction, while alternating current reverses direction many times per second. 14 NC Department of Public Instruction

15 Phy Analyze electric systems in terms of their energy and power The CD player plugged into the auxiliary outlet in Ellen s car has a resistance of 6.0 Ω. a) How much current does the CD player draw when it is run off the car s 12 V battery? b) How much power does the CD player use? Support your answer with an explanation and reasoning for How is electric power and electrical energy related? a. Electric power is the rate that electrical energy is used to do mechanical or thermodynamic work. b. Electrical energy is randomly reduced by electric power to perform work. c. Electric energy is transferred by an insulator which produces electrical power for heat to operate machines. d. Electric power increases electrical energy when transferred through a resistor in a circuit. Phy Analyze systems with multiple potential differences and resistors connected in series and parallel circuits, both conceptually and mathematically, in terms of voltage, current and resistance The diagram represents a DC circuit. R 1 A E R 2 R 3 B The total resistance of the circuit is 10.5 Ω. R 2 and R 3 each has the same resistance of 5.0 Ω. What is R 1? a. 4.0 Ω b. 5.0 Ω c. 8.0 Ω d Ω 15 NC Department of Public Instruction

16 2.3.5 What is the equivalent resistance of a 4.0-Ω resistor, a 5.0-Ω resistor and a 6.0-Ω connected in parallel? a Ω b. 5.0 Ω c Ω d. 3.5 Ω 16 NC Department of Public Instruction

17 Interactions of Energy and Matter Essential Standards Clarifying Objectives Assessment Examples Phy.3.1Explain charges and electrostatic systems. Phy Explain qualitatively the fundamental properties of the interactions of charged objects Explain why small pieces of paper are attracted to a comb that has been rubbed through hair What does it mean to say that charge is conserved in a closed system? Your answer should include an example electrostatic system and explanation of the interaction. Phy Explain the geometries and magnitudes of electric fields Which is true about electric field lines? a. They form a counter-clockwise circle around positive charges. b. They form a clockwise circle around positive charges. c. They radiate outward from negative charges. d. They radiate outward from positive charges What determines the strength of an electric field? Phy Explain how Coulomb s law relates to the electrostatic interactions among charged objects What is the electrostatic force of attraction between a proton and an electron that are separated by 3.25 x 10-7 m? a. 1.0 x 10-7 N b. 1.5 x 10-7 N c x N d x10-15 N 17 NC Department of Public Instruction

18 3.1.3 The diagram represents three charged particles arranged in a line. Describe the forces acting on particle 3 and calculate the magnitude and direction of the net force. Explain your Phy Explain the mechanisms for producing electrostatic charges, including charging by friction, conduction, and induction What will be the effect of a negatively charged rod touching a neutral electroscope? a. The leaves will fall. b. The electroscope will become positively charged. c. There will be no change. d. The leaves will spread apart How does charging by conduction and induction occur during a thunderstorm? Explain your answer. Phy Explain how differences in electrostatic potentials relate to the potential energy of charged objects The electric field intensity between two charged plates is 3.00 x 10 4 N/C. The plates are m apart. What is the electric potential difference between the plates? a x 10 3 V b x 10 3 V c x 10 3 V d x 10 3 V Support your answer with an explanation and reasoning for 18 NC Department of Public Instruction

19 3.1.5 The diagram shows a positive test charge near a positive point charge. What happens if a positive test charge moves from point A to point B in the electric field? Explain your answer in reference to: potential energy, electric potential and force. 19 NC Department of Public Instruction

20 Phy.3.2 Understand the concept of magnetism. Phy Explain the relationship between magnetic domains and magnetism Explain how an unmagnetized iron bar becomes magnetized when placed in a magnetic field. Your answer should include a diagram to illustrate magnetic domains and an explanation of their origin. Phy Explain how electric currents produce various magnetic fields The diagram shows the magnetic field around a current bearing wire. Explain the relationship between the electric current in the wire and the magnetic field (both magnitude and direction) If the current in a wire is doubled, what happens to the strength of the magnetic field? a. Magnetic field strength is half of the original value. b. Magnetic field strength is one-third of the original value. c. Magnetic field strength is the same. d. Magnetic field strength is double the original value. Phy Explain how transformers and power distributions are application of electromagnetism The diagram represents a simple transformer. 20 NC Department of Public Instruction

21 Explain how a step-down transformer is used to change the voltage of power lines from 220 kv to an output voltage of 110V for electrical outlets inside homes How does the magnetized strip on the credit card work? Explain your answer Explain the process of electromagnetic induction involved in electric generators. 21 NC Department of Public Instruction