8.2 Power

Which of these is a measure of force?

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

You move a 12-newton box up a 6-meter ramp. In order to find out how much power you created, what would you need to know?

• The mass of the box
• The slope of the ramp 
• The direction the box moved
• How long the task took

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

Which of the following would produce the most power?

• A mass of 10 kilograms lifted 10 meters in 10 seconds 
• A mass of 10 kilograms lifted 10 meters in 5 seconds
• A mass of 5 kilograms lifted 10 meters in 5 seconds
• A mass of 5 kilograms lifted 5 meters in 10 seconds

Work divided by time equals...

• energy
• power

The unit of power is the...

• work
• watt

Force multiplied by distance equals...

• work
• power

Power is the RATE at which work is done. 

• True
• False

If you lift a box from the floor to a height of 1m and then carry the for for 10m, you do work only when you CARRY the box.

• True
• False