Power Problems

The SI Unit for Power

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

What is the formula for Power?

• E=mc²
• W= F x d
• P = W/T

W = 500 Joules 
t = 25 seconds
P = ???

• 0.05 W
• 20 W
• 12500 W
• 2000 W

How much time is needed to produce 720 Joules of work if 90 watts of power is used? 

• 0.125 s
• 8 s
• 64800 s
• 80 s

A person weighing 600 N gets on an elevator. The elevator lifts the person 6 m in 10 seconds.  How much power was used?

• 360 W 
• 60 W
• 3600 W
• 600 W

A kid applies a force of 70 N to a ball over 1.1 meters in 0.001. How much power did he generatel?

• 77,000 W

• 77 W

• 700 W

• 770 W

A weightlifter lifts two 300 newton weights 1.5 meters off the ground in 5 seconds. How much work has he done?

• 180 J

• 180 W

• 900 J

• 900 W

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

Tags

NGSS.HS-PS3-1

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