Power

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

• 30 watts

• 3 watts

• 120 watts

• 270 watts

If 68 W of power is produced in 18 seconds, how much work is done?

• 1,224 J

• 0.264 J

• 3.77 J

• 12.24 J

Tags

NGSS.HS-PS3-1

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

What is the difference between calculating power and work?

• Power takes into account the time it takes to complete a task
• Work takes into account the time it takes to complete a task
• Power is force/area
• Work is force/area

Which picture shows more power?

• 
• 

Tags

NGSS.MS-PS3-5

Which picture shows more power?

• 
• 

Two workers use 100 N of force to move a sofa 2 meters in 2 seconds. How much power is required?

• 100 watts

• 400 watts

• 104 watts

• 50 watts

A crane lifts an 8-m long steel girder weighing 2600 N up 15 m off the ground. The crane did ___ of work.

• 0 J

• 39000 J

• 20800 J

• 2600 J

Tags

NGSS.MS-PS3-5

NGSS.MS-PS3-4

Is this an example of work? 
A waiter carries a tray full of meals above his head by one arm straight across the room at constant speed. 

• True
• False

The SI unit for power is...?

• Watts
• Joules
• Newtons
• Meters