Lesson 7: Momentum and Impulse
Overview:
Momentum is a word often used in our everyday language, but in physics it has a specific meaning and even its own formula. In this lesson you will be introduced to it, and also impulse. It should help you when playing contact sports, such as football!!
Curriculum Expectations:
Overall Expectations:
C1. Analyze, and propose ways to improve, technologies or procedures that apply principles related to energy and momentum, and assess the social and environmental impact of these technologies or procedures.
C3. Demonstrate an understanding of work, energy, momentum, and the laws of conservation of energy and conservation of momentum, in one and two dimensions.
Specific Expectations:
C1.1 Analyze, with reference to the principles of energy and momentum, and propose practical
ways to improve, a technology or procedure that applies these principles (e.g., fireworks, rocket propulsion, protective equipment, forensic analysis of vehicle crashes, demolition of buildings).
C1.2 Assess the impact on society and the environment of technologies or procedures that apply the principles of energy and momentum (e.g., crumple zones, safety restraints, strategic building implosion).
C2.1 Use appropriate terminology related to energy and momentum, including, but not limited to:
work, work–energy theorem, kinetic energy, gravitational potential energy, elastic potential energy, thermal energy, impulse, change in momentum–impulse theorem, elastic collision, and inelastic collision.
C2.5 Analyze, in qualitative and quantitative terms, the relationships between mass, velocity, kinetic energy, momentum, and impulse for a system of objects moving in one and two dimensions (e.g., an offcentre collision of two masses on an air table, two carts recoiling from opposite ends of a released spring), and solve problems involving these concepts.
C2.7 Conduct laboratory inquiries or computer simulations involving collisions and explosions in one and two dimensions (e.g., interactions between masses on an air track, the collision of two pucks on an air table, collisions between spheres of similar and different masses) to test the laws of conservation of momentum and conservation of energy.
C1. Analyze, and propose ways to improve, technologies or procedures that apply principles related to energy and momentum, and assess the social and environmental impact of these technologies or procedures.
C3. Demonstrate an understanding of work, energy, momentum, and the laws of conservation of energy and conservation of momentum, in one and two dimensions.
Specific Expectations:
C1.1 Analyze, with reference to the principles of energy and momentum, and propose practical
ways to improve, a technology or procedure that applies these principles (e.g., fireworks, rocket propulsion, protective equipment, forensic analysis of vehicle crashes, demolition of buildings).
C1.2 Assess the impact on society and the environment of technologies or procedures that apply the principles of energy and momentum (e.g., crumple zones, safety restraints, strategic building implosion).
C2.1 Use appropriate terminology related to energy and momentum, including, but not limited to:
work, work–energy theorem, kinetic energy, gravitational potential energy, elastic potential energy, thermal energy, impulse, change in momentum–impulse theorem, elastic collision, and inelastic collision.
C2.5 Analyze, in qualitative and quantitative terms, the relationships between mass, velocity, kinetic energy, momentum, and impulse for a system of objects moving in one and two dimensions (e.g., an offcentre collision of two masses on an air table, two carts recoiling from opposite ends of a released spring), and solve problems involving these concepts.
C2.7 Conduct laboratory inquiries or computer simulations involving collisions and explosions in one and two dimensions (e.g., interactions between masses on an air track, the collision of two pucks on an air table, collisions between spheres of similar and different masses) to test the laws of conservation of momentum and conservation of energy.
Success Criteria:
 What is linear momentum and how do we calculate it?
 Since momentum is a vector quantity. How do we determine the direction of it?
 Derive the formula for impulse using a collision of two masses and Newton's third law.
 What is impulse and how do we calculate it?
 Since impulse is a vector quantity, how do we determine the direction of it?
 What does the area under a forcetime graph measure?
 Can we approximate the impulse produced by a variable force by assuming a constant average force acting over the same interval?
Time Allocation: 2 hour
Learning A
ctivities:Read pages 222  226 from Nelson 5.1 and copy the sample problems into your notes.
In the playlist below, video:
 Will introduce you to impulse and momentum in physics.
 Will connect car safety with impulse by comparing old cars vs. new cars.
 Will show you how to analyze impulse in a graphical format.
 Will find F=? when a ball strikes a wall, example 1.
 Will find F=? when a ball strikes a wall, example 2.
Practice questions 1 and 2 on page 223.
Practice question 1 on page 226.
Practice question 1 on page 226.
Task:
Solve questions 5, 8, and 9 from Nelson 5.1 Review on page 227.
Optional Extension:
Optional Extension:
 Solve questions 11 and 12 on page 227.
 Practice question 2 on page 226.
Reflect:
For traffic safety, is it better to have a traffic light pole that crumples in place or one that shears off at its base when a vehicle crashes into it? Explain your reasoning.
Additional Resources:
Will explain an apparent "contradiction" to momentum is ALWAYS conserved.

