Work and 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

What does one newton exerted over a distance of one meter equal?

• One watt
• One hertz
• One volt 
• One joule 

A kid applies a force of 70 N to a ball over 1.1 meters (force and displacement in the same direction). 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 

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 five meters in 4 seconds. How much power have you generated?

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

Work divided by time equals...

• energy
• power

The unit of work is the ...

• joule

• watt

The unit of power is the...

• work
• watt

Force multiplied by distance equals...

• work
• power