Work and Power Calculations

The SI Unit for Work

• Newton (N)
• Joule (J)
• Second (s)
• Watt (W)

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

Work is done when a weightlifter holds a barbell still above his head.

• True
• False

You push against the back of your friends car that is stuck. You push and be become very tired, but the car does not move. Did you do work?

• Yes, work was done

• No, work wasn't done

The amount of work done in a certain amount of time is known as 

• work
• effort force
• resistance force 
• power

How much work is done in holding a 15 N sack of potatoes while waiting in line at the grocery store for 3 minutes?

• 15 J
• 45 J
• 0 J
• 5 J

The unit used to measure power is the 

• Watt
• Newton
• Joule
• Newton*meter

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