Work & Power

Which of the following is a true statement about work?

• It measures how quickly an object accelerates 
• It measures how much force is applied over a certain distance

• It measures the change in an object's rate of speed
• It measures how much time it takes to move a massive object

A kid applies a force of 70 N to a ball over 1.1 meters. How much work did he do on the ball? 

• 77 J
• 7.7 J 
• 0.7 J 
• 770 J 

A weightlifter lifts two 300 newton weights 1.5 meters off the ground. How much work has he done?

• 600 J 
• 660 J
• 900 J 
• 1200 J 

Which of these is a measure of force?

• 100 newtons
• 100 meters per second
• 100 joules
• 100 watts

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

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

You move an 8-newton weight 5 meters in 4 seconds. How much power have you generated?

• 160 watts
• 10 watts
• 6.4 watts
• 17 watts

How much work is being done with 200 N of force over 426 meters?

• 85,200 J
• 45,620 J
• 90,480 J
• 62,329 J

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

Which of the following is the best example of work being done.

• doing homework

• lifting a box

• pushing a stationary box

• holding a box

In which of these cases is work being done? 

• A student sleeps
• A student pushes a locked door that does not move
• a student carries his chair into another room
• A student sits on the carpet