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Assignment #4.3 Energy, Work, and Power

Name: _______________________________________________________ Period: _________

**Learning Targets **

**I can define energy, work and power **

**I can calculate the work done on an object **

**I can calculate the power output of an object **

**Energy **

Energy is defined as the ability to do __________________.

Energy is measured in __________________.

The amount of energy required to lift a __________________1 m is approximately = 1 __________________.

**Work **

Work is done on an object when a __________________ is applied and the object moves some __________________.

The equation for work is:

W =

W = work and is measured in __________________

F = force and is measured in __________________ d = distance and is measured in __________________

Work is also measured in __________________ because it takes

__________________ to do work.

**Power **

Power is defined as the ________________ at which ________________ is done… or how much work is accomplished in ________________.

The equation for power is:

P =

P = power and is measured in __________________ which also equals a

__________________ per __________________

W = work and is measured in __________________ t = time and is measured in __________________

R:

C:

G:

E:

Assignment #4.3 Energy, Work, and Power

**Practice Problem **

Johnny pushes his brother across the parking lot with a force of 40 N covering a distance of 20 meters in 10 seconds. a) How much work did Johnny do?

R:

C:

G: b) How powerful is Johnny in this case?

E:

Assignment #4.3 Energy, Work, and Power

**NOW FILL THE FACTS YOU LEARNED INTO YOUR ESSENTIAL FACTS BOOKLET FOR UNIT 4! **

Name _____________________________________________________________ Period _____

**Directions: Solve each of the following problems using the GERC format. **

1) A force of 50 N is applied to a box and slid across the floor 5 meters. Determine the amount of work that is done on the block.

2) Bob is able to carry 10 boxes, each weighing 15 N up a flight of stairs 5 meters in 45 seconds. a. Determine the amount of work that Bob accomplished. b. Determine how powerful Bob is in performing the work calculated above.

3) A 75 watt light performs how much electrical work in one minute. (Convert 1 minute to seconds first!)

Assignment #4.3 Energy, Work, and Power

4) A 540 kg sports car accelerates a car at 8 m/s 2 for 8.5 seconds while covering 750 m. What force is required to achieve this acceleration?

5) How much work does the car do to cover 750 m?

6) How powerful is the engine in the sports car?