## Lesson 2: Kinetic Energy and Work Energy Theorem

## Overview:

This lesson will combine everything we have learned thus far, into one simple and beautiful equation.

## Curriculum Expectations:

**Overall Expectations:**

**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:**

**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.

**C2.2**Analyze, in qualitative and quantitative terms, the relationship between work and energy, using the work–energy theorem and the law of conservation of energy, and solve related problems in one and two dimensions.

**C2.3**Use an inquiry process to analyse, in qualitative and quantitative terms, situations involving work, gravitational potential energy, kinetic energy, thermal energy, and elastic potential energy, in one and two dimensions (e.g., a block sliding along an inclined plane with friction; a cart rising and falling on a roller coaster track; an object, such as a mass attached to a spring pendulum, that undergoes simple harmonic motion), and use the law of conservation of energy to solve related problems.

## Success Criteria:

- What is kinetic energy and how do we calculate it?
- Describe the work-kinetic energy theorem and include how it is useful?
- The work-kinetic energy theorem is only valid if no energy losses occur. Describe where the energy may go?
- Does the work-kinetic energy theorem hold if the applied force is not constant?

## Time Allocation: 2 hour

## Learning A

ctivities:**Read**pages 171 - 175 from Nelson 4.2 and

**copy the sample problems**into your notes.

In the playlist below, video:

- Will show you how to find the work and kinetic energy pushing an object horizontally on a frictionless surface.

**Practice**questions 2 and 3 on page 172.

**Practice**

**question 1 on page 175.**

## Task:

**Solve**questions 2, 4, 7, and 9 from Nelson 4.2 Review on page 176.

*Optional Extension:*- Solve questions 8, 10, 11, and 12 on page 176.
- Practice

## Reflect:

Could an elephant walking slowly across a field have more kinetic energy than a cheetah chasing its prey? Explain your answer.