Author:
Michele Langhans

Students will determine the relationship between work and power.

This is your notes.

Tutorial

Here are the calculations for work and power.

Source: various educators and Langhans

1. The unit for force is ____________ , the unit for distance is _________and the unit for work is __________.

2. Identify the following as work OR no work:

a. pushing a chair across the floor

b. holding a wet platapus over your head

c. I am holding a 2 kg block of cheese in my hands. I walk 12 m to the other side of the room

d. lifting up a box

3. Explain if the following scenarios have any work involved:

a. I decide to get my pet frog to do a little weight lifting (but I’m going to start him off slow!). He lifts 10 kg up from the floor, over his head, and back down to the floor.**Explain** if he did any work.

b. Last winter my car got caught in a snow bank. I promise one of my friends that if he comes over to do some work for me, I’ll buy him a Whopper (with extra onions… he really likes onions). We get behind the car and push it out of the snow.**Explain** if I owe him a Whopper.

c. A batter hits two baseballs with the same force. One hits the ground near third base. The other is a home run out of the park. Where was there more work done?

4. What is the relationship between power and work?

5. Describe a scenario show the relationship between work and power.

6. A teacher pushed a 10 kg desk across a floor for a distance of 5 m. Her force is 20 N. How much work was done?

7. What is the amount of work done if 35 N of effort are used to move a trash can 15 m?

8. How much work has been done when 60 N of effort was used to push a computer 2.5 m?

9. If it takes 726 watts of power to move a mass 36 meters in 14 seconds, what is the mass?

10. How much power is used to move a 25 kg mass 8 meters in 15 seconds?

11. How long does it take to do 278 Joules of work with 17 watts?

12. If an object has a mass of 47 kg and it is moved 27 meters in 60 seconds, how much power was used?

13. What is the mass of an object if it took 270 J of work to move it 15 meters?

14. How much power is used to move a 5 kg mass 28 meters in 8 seconds?

Source: various educators and Langhans