All Lessons. Lesson 1 Galileo and N1

Transcription

1 All Lessons Lesson 1 Galileo and N1 Curriculum Expectations C3.2 explain how the theories and discoveries of Galileo and Newton advanced knowledge of the effects of forces on the motion of objects C3.3 state Newton s laws, and apply them, in qualitative terms, to explain the effect of forces acting on objects Learning Goals We are learning: About Aristotle vs Galileo About N1 velocity is constant until force About Inertia Lesson Overview (Teaching Strategies) History of Aristotle/Galileo People in antiquity had experienced forces on a daily basis. They had an intuitive understanding of mass and the strength required to move objects. Even before modern science they were able to construct tools and build large and intricate structures. Learning Environment The tables are arranged in such a way that students are sitting in groups of 4-6. This allows students to do group work and work with partners effectively. It also allows for easy transitions between instruction time and group discussions. Students with special needs must be accommodated for. For example, a student with visual impairment may be assigned a seat that is closer to the board or the particular activity at hand. Success Criteria I can: Explain the differences between Aristotle s and Galieleo s theories of motion. Describe the effect of friction on motion Explain the concept of inertia Explain how objects behave according to Newton s 1 st law explain what a force does to an object. Assessment/Evaluation Groups perform inertia demonstrations and explain to the class Ticket out the door Define inertia (1 mark KU)

2 Aristotle s concept of motion and other relevant aspects of the universe: In order to move objects, a force must be applied throughout the entire time the object is in motion. Without the application of force, objects immediately stop moving and come to a rest. All of matter is composed of the 4 elements (earth, air, fire, water) all of which have a natural place of rest in the universe. Depending on an object s elemental composition, it will move to return to its natural place of rest. Projectiles have a constant force applied to them as they move. Forward movement creates an empty space behind the object. Air rushing in to fill the space pushes on the projectile and encourages its motion. (italicized points are not pertinent for this lesson save for the lesson on gravity) All objects fall at a constant speed they do not accelerate. Heavier objects fall faster than lighter ones. Galileo s experiment: Countered Aristotle s view Discovered the effect of friction Contemplated the effect of gravity Discovered that objects move at constant velocity eternally until forced otherwise (italicized points are not pertinent for this lesson save for the lesson on gravity) Tested downwards motion of objects. Objects of different masses accelerate due to gravity with constant acceleration, regardless of their mass Some objects experience greater air resistance and may feel a smaller net force Technology/ Materials Projector Laptop with Sketchbook Express Software Wacom Bamboo Tablet for sketching Pennies Flat ruler Playing cards Plastic cups Paper plates Bowls Ping pong balls Golf balls Paper towel cardboard roll Small carts Textbooks Sheets of paper Table cloth Several newspaper sheets Tape 1/8 thick, 2 foot long basswood board

3 Galileo s Law of Inertia: Objects travel at constant speed in a straight line unless their state of motion is changed by an external net force. Inertia: Iners = latin for idle. Inertia = an objects resistance to a force that would change its state of motion. The property of inertia is directly dependent on an object s mass. Inertia Demonstrations: Pennies + ruler Penny on card Paper under bottle Table cloth trick Board + newspaper

4 Lesson 2 Newton s 2 nd Law Curriculum Expectations C2.3 conduct an inquiry into the relationship between the acceleration of an object and its net force and mass (e.g., view a computer simulation of an object attaining terminal velocity; observe the motion of an object subject to friction; use electronic probes to observe the motion of an object being pulled across the floor), and analyse the resulting data [PR, AI] C3.3 state Newton s laws, and apply them, in qualitative terms, to explain the effect of forces acting on objects Learning Goals We are learning: About the relationship between acceleration, mass, and net force About force units - Newtons Lesson Overview (Teaching Strategies) Demonstrate that force is a measurable quantity Explain: Acceleration depends on force Acceleration depends on mass Observe F = ma with lab. Perform the lab as a class: Cart being dragged along the table Learning Environment The tables are arranged in such a way that students are sitting in groups of 4-6. This allows students to do group work and work with partners effectively. It also allows for easy transitions between instruction time and group discussions. Students with special needs must be accommodated for. For example, a student with visual impairment may be assigned a seat that is closer to the board or the particular activity at hand. Success Criteria I can: Determine an object s acceleration based on its mass and the force acting on it Perform an informal demonstration to explain the relationship between acceleration, mass, and force Assessment/Evaluation Do now - state the law of inertia (1 mark KU) Assess students based on informal lab questions Ticket out the door which two factors affect an object s acceleration? (1 mark KU)

5 Masses of different weight hang off the table and pull the cart with different force. Laser analyzes the motion of the cart. Plot the relationship. (see lab ford details: While the lab is being performed, interject questions that involve critical thinking regarding the phenomenon: How fast will the cart move if we double the hanging mass? Twice as much acceleration is doubled Why exactly is the acceleration doubled? The hanging mass doubles the pulling force What will occur if we add mass to the cart? Fnet=ma Newton was the first to give forces a unit. He coined it the newton. Unit of force = N 1N = 1kgm/s 2 Technology/ Materials Projector Laptop with Sketchbook Express Software Wacom Bamboo Tablet for sketching Lab equipment Pasco Dynamics Track and Two Carts Force sensor mount for dynamics cart Smart Pulley Force Sensor Hooked Weight Set Cart Accessory Weight String & Scissors Table Clamp, Rods and Clamps Computer Data Studio and Graphical Analysis

6 Lesson 3 Forces as vectors Curriculum Expectations C3.1 distinguish between, and provide examples of, different forces (e.g., friction, gravity, normal force), and describe the effect of each type of force on the velocity of an object C2.5 plan and conduct an inquiry to analyse the effect of forces acting on objects in one dimension, using vector diagrams, free-body diagrams, and Newton s laws [IP, PR, AI, C] C2.2 conduct an inquiry that applies Newton s laws to analyse, in qualitative and quantitative terms, the forces acting on an object, and use free-body diagrams to determine the net force and the acceleration of the object [PR, AI, C] Learning Goals We are learning: That a force is a push/pull About different types of forces (gravity, applied, friction ) That forces are vectors Fnet = F1 + F2 + F3 Lesson Overview (Teaching Strategies) What are examples of forces? List common forces. Force of gravity Applied Force Force of Friction Normal Force Tension force Electromagnetic force Learning Environment The tables are arranged in such a way that students are sitting in groups of 4-6. This allows students to do group work and work with partners effectively. It also allows for easy transitions between instruction time and group discussions. Students with special needs must be accommodated for. For example, a student with visual impairment may be assigned a seat that is closer to the board or the particular activity at hand. Success Criteria I can: List common forces Use a FBD to calculate net force Calculate a net force from applied forces Assessment/Evaluation Do now N2 question (1 mark KU) Ongoing class input Ticket out the door given an FBD, find the net force (1 mark KU) Technology/ Materials Projector Laptop with Sketchbook Express Software

7 Different forces can be applied on the same object: Draw a FBD. Demo: Strings attached to a ring People pulling/pushing on an object/person. Wacom Bamboo Tablet for sketching Strings Ring. Analyze 1D effect. Analyze 2D effect Draw a FBD Solve 1D and 2D problems: Fnet = F1 + F2 + F3

8 Lesson 4 Force of Gravity Curriculum Expectations C2.6 analyse and solve problems involving the relationship between the force of gravity and acceleration for objects in free fall [AI] C3.4 describe, in qualitative and quantitative terms, the relationships between mass, gravitational field strength, and force of gravity Learning Goals We are learning: About acceleration due to gravity About gravitational acceleration on other planets About the force of gravity About the universal gravitational constant Lesson Overview (Teaching Strategies) LAB: Ticker tape (see lab document for details) Measure acceleration due to gravity g = 9.8m/s 2 How about acceleration on other planets. Saturn? Moon? Mars? The planet isn t physically applying a force. No one is touching you. How is the force being applied? A: simply by having mass. Learning Environment The tables are arranged in such a way that students are sitting in groups of 4-6. This allows students to do group work and work with partners effectively. It also allows for easy transitions between instruction time and group discussions. Students with special needs must be accommodated for. For example, a student with visual impairment may be assigned a seat that is closer to the board or the particular activity at hand. Success Criteria I can: Calculate the magnitude of gravitational force between two masses Calculate the force of gravity on an object at Earth s surface Assessment/Evaluation Do now based on a FBD, find net force and acceleration (1 mark APP) Ongoing class input Ticket out the door what is the acceleration due to gravity on Earth s surface? (1 mark KU) Technology/ Materials Projector Laptop with Sketchbook Express Software Wacom Bamboo Tablet for sketching

9 Draw two spheres to represent masses, and a line between them. Force of equal magnitude applied to both. The forces are on the imaginary line, applied towards each other. Lab equipment: Ticker timer, ticker tape, mass sets, meter stick, old physics text If one mass is 10kg, and the other is 100kg, which will move faster? a=f/10 a=f/100 Draw that over time the smaller mass moves faster than the bigger one. What is the force exactly? Fg between two masses (opposite directions) Fg = Gmm/d 2 G is a very small number. G is the universal gravitational constant. Do problems solve for Fg = Gmm/d 2

10 Lesson 5 Gravity Curriculum Expectations C2.6 analyse and solve problems involving the relationship between the force of gravity and acceleration for objects in free fall [AI] C3.4 describe, in qualitative and quantitative terms, the relationships between mass, gravitational field strength, and force of gravity Learning Goals We are learning: About the force of gravity acting on two masses at a certain distance from each other About gravitational field intensity on the surface of planets About mass and weight Lesson Overview (Teaching Strategies) Review F=Gmm/d2 Proportionality questions. Given two masses, find Fg, and find acceleration for each. Demonstrate that g = GM/R 2 Learning Environment The tables are arranged in such a way that students are sitting in groups of 4-6. This allows students to do group work and work with partners effectively. It also allows for easy transitions between instruction time and group discussions. Students with special needs must be accommodated for. For example, a student with visual impairment may be assigned a seat that is closer to the board or the particular activity at hand. Success Criteria I can: Perform proportional analysis calculations involving Fg and g Distinguish between weight and mass Calculate the gravitational field intensity on the surface of a planet Assessment/Evaluation Do now what is the equation for the magnitude of the gravitational force between two masses? (1 mark KU) Ongoing class input Ticket out the door The force of gravity on Mr. Gordon is 650N. What are his weight and mass? Show that Fg = mg Gravitational field intensity g = 9.8m/s 2 = 9.8 N/kg

11 Mass vs weight Technology/ Materials Projector Laptop with Sketchbook Express Software Wacom Bamboo Tablet for sketching

12 Lesson 6 Newton s 3 rd Law Curriculum Expectations C3.3 state Newton s laws, and apply them, in qualitative terms, to explain the effect of forces acting on objects C2.4 analyse the relationships between acceleration and applied forces such as the force of gravity, normal force, force of friction, coefficient of static friction, and coefficient of kinetic friction, and solve related problems involving forces in one dimension, using free-body diagrams and algebraic equations (e.g., use a drag sled to find the coefficient of friction between two surfaces) [AI, C] C2.5 plan and conduct an inquiry to analyse the effect of forces acting on objects in one dimension, using vector diagrams, free-body diagrams, and Newton s laws [IP, PR, AI, C] Learning Goals We are learning: About action-reaction forces About the Normal Force Lesson Overview (Teaching Strategies) When you touch things, why do you feel them? The harder you press on something, the more pressure you feel on your hand. You re the one that s applying force onto the object. It s inactive. You are the one who is initiating the action. Nevertheless, you feel the object s reaction you feel a force back on you. If you try to drag a heavy object by pulling on a rope, it may feel like it s pulling you back it is. Learning Environment The tables are arranged in such a way that students are sitting in groups of 4-6. This allows students to do group work and work with partners effectively. It also allows for easy transitions between instruction time and group discussions. Students with special needs must be accommodated for. For example, a student with visual impairment may be assigned a seat that is closer to the board or the particular activity at hand. Success Criteria I can: Explain Newton s 3 rd law Identify action-reaction pairs of forces Draw FBD s involving action-reaction forces Assessment/Evaluation Do now How much force does a penguin exert on the ground if its mass is 20kg? (1mark KU) Think-pair-share responses Problem take-up Ticket out the door draw a FBD of the forces on a 20kg penguin. Calculate the value of the forces. (1 mark KU)

13 Every force that is ever applied by object A on object B brings about another force a force applied by object B back on A, equal in magnitude and opposite in direction. Newton s 3 rd law. ALL FORCES EXIST IN PAIRS. Demonstration helicopter air plane Launch a propeller air plane. How come this plane can fly? Think-pair-share As the propeller spins, it applies a force on the air. The air applies a force equal in magnitude back on the propeller at the exact same instant. The air pushing on the propeller allows the helicopter plane to fly. Technology/ Materials Projector Laptop with Sketchbook Express Software Wacom Bamboo Tablet for sketching Toy helicopter plane Objects to push on: Masses of different weight. Textbook problem: Pushing boxes problem. Take it up with the class. Explain that a force can be applied either by pushing or by pulling. The action-reaction phenomenon occurs regardless. Textbook problem: pulling problem.

14 Lesson 7 Friction Curriculum Expectations C2.3 conduct an inquiry into the relationship between the acceleration of an object and its net force and mass (e.g., view a computer simulation of an object attaining terminal velocity; observe the motion of an object subject to friction; use electronic probes to observe the motion of an object being pulled across the floor), and analyse the resulting data [PR, AI] C2.4 analyse the relationships between acceleration and applied forces such as the force of gravity, normal force, force of friction, coefficient of static friction, and coefficient of kinetic friction, and solve related problems involving forces in one dimension, using free-body diagrams and algebraic equations (e.g., use a drag sled to find the coefficient of friction between two surfaces) [AI, C] Learning Goals We are learning: About static and kinetic friction About the coefficient of friction About the relationship between the force of friction and the normal force Lesson Overview (Teaching Strategies) Review Aristotle What was his view of motion? - Things stop if there s no force applied What did Aristotle not take into account? - Friction Learning Environment The tables are arranged in such a way that students are sitting in groups of 4-6. This allows students to do group work and work with partners effectively. It also allows for easy transitions between instruction time and group discussions. Students with special needs must be accommodated for. For example, a student with visual impairment may be assigned a seat that is closer to the board or the particular activity at hand. Success Criteria I can: Distinguish between static and kinetic friction Calculate the force of friction on an object given its mass and the COF. Assessment/Evaluation Do now a man is pulling on a rope tied to a house. Draw the FBD for the man and the house (1 mark KU) Ongoing class input Do they recall aristotle s view? Ticket out the door what are the two types of friction? (1 mark KU)

15 Friction What is friction? Interaction between surfaces. The greater (or rougher) the interaction, the greater the friction. Which direction is the force of friction? Tangent to the interacting surfaces, opposing the direction of the moving object. Resource: What does friction depend on? Perform basic friction demos. - Friction depends on the type of surfaces interacting (roughness) - Friction depends on the amount of contact between them (perpendicular contact) Notice what angle your arms are at when you try to rub your hands together as hard as possible. Technology/ Materials Projector Laptop with Sketchbook Express Software Wacom Bamboo Tablet for sketching Friction simulation Phet Rubber band demonstration materials: Long rubber band Pencil cart Sliding object lab materials: Long wooden board An object to slide (textbook, cube of foam) Coefficient of friction Perpendicular force normal force Ff = Fn * COF Static vs Kinetic friction Rubber band cart demo The band elongates in order to move the cart. Once its moving, the rubber band shortens slightly.

16 Lesson 8 Technology Curriculum Expectations C1.1 analyse, with reference to Newton s laws, a technology that applies these laws (e.g., extremely low friction bearings, near frictionless carbon, different types of athletic shoes, roller coasters), and propose ways to improve its performance [AI, C] C1.2 evaluate the impact on society and the environment of technologies that use the principles of force (e.g., prosthetics, plastic car bodies) [AI, C] Learning Goals We are learning: About the application and impact of newton s laws in technology Lesson Overview (Teaching Strategies) Review friction Tires skidding on wet roads. Breaks require more surface interaction to increase efficiency (friction) Review all concepts before the test. Try complex problems Newton s 3 rd law problems with friction. Learning Environment The tables are arranged in such a way that students are sitting in groups of 4-6. This allows students to do group work and work with partners effectively. It also allows for easy transitions between instruction time and group discussions. Students with special needs must be accommodated for. For example, a student with visual impairment may be assigned a seat that is closer to the board or the particular activity at hand. Success Criteria I can: Assessment/Evaluation Do now A man pushes a box on a level surface. Draw a FBD of all the forces acting on the box. (1 mark APP) Ongoing class input Ticket out the door Technology/ Materials Projector Laptop with Sketchbook Express Software Wacom Bamboo Tablet for sketching