Work and Power

Multiple Choice

Which is the correct unit for work?

• Joules

• Newton

• meter

• Watts

Multiple Choice

Work is done only if

• a force is applied.

• the force applied causes the object's motion.

• an object is in motion.

Multiple Choice

It took 50 Joules to push a chair 5 meters across the floor. With what force was the chair pushed?

• 10 N

• 0.1 N

• 250 N

• 1 N

Multiple Choice

If 40 N of force is applied to a 10 kg cart over a distance of 50 meters, how much work is done?

• 8000 J

• 8000 N

• 4000 J

• 2000 J

Multiple Choice

You do 90 joules of work in 30 seconds. How much power have you generated?

• 30 watts
• 3 watts
• 120 watts
• 270 watts

Multiple Choice

If 68 Joules were necessary to move a 4 Newton crate, how far was the crate moved?

• 272 m
• 17 m
• 4.05 m
• 272 cm 

Multiple Choice

If 150 Joules of work is needed to move a box 10 meters, what force was used? 

• 1500 N
• 15 N
• 1.5 N
• 150 N

Multiple Choice

A 100 N force is applied to move an object a horizontal distance of 5 meters at constant speed in 10 seconds. How much power is done?

• 50J

• 50W

• 500J

• 500W

Multiple Choice

Sarah climbs 3 meters up a rope in 10s. Keani climbs 3 meters up a rope in 7s. Which student did more work?

• Sarah

• Keani

• They did the same amount.

• Neither did any work.

Multiple Choice

Sarah climbs 3 meters up a rope in 10s. Keani climbs 3 meters up a rope in 7s. Which student used more power?

• Sarah

• Keani

• They did the same amount.

• Neither used any power.

Work and Power Summary

Work happens when a force is applied to an object and causes it to move.

Work = Energy (Both measured in joules)

Power is a measure of how fast you do work or use energy.

(Measured in watts)

Think of work as being more focused on how far you move something and power focused on how fast you move something.