Work & Power

Select all: Work is equal to...

• KE + PE

• Change in energy

• mg

• Fd

Tags

NGSS.HS-PS3-2

Bobby lifts a book to the second floor in 20 seconds. Carol lifts the same book to the second floor in 10 seconds. Who did more work?

• Bobby

• Carol

• They did the same amount of work

• Not enough information

Tags

NGSS.MS-PS3-2

NGSS.MS-PS3-4

A girl weighs 400 N. She runs up a flight of stairs of height 5 m in 4 seconds. Her power is:

• 320 W

• 400 W

• 500 W

• 2 000 W

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-4

How do you calculate power?

• P = W/t
• P = E/t
• P = w * t
• P = bbq/chicken

A 5000N block is lifted 10 m. How much work was done?

• 50000 J
• 5000 J
• 500 J
• 50 J

Which of the following is defined as an energy transfer?

• kinetic energy

• work

• potential energy

• chemical energy

Tags

NGSS.HS-PS3-4

A light plastic cart and a heavy steel cart are both pushed with the same force for a distance of 1.0 m, starting from rest. After the force is removed, the kinetic energy of the light plastic cart is ________ that of the heavy steel cart.

• greater than

• equal to

• less than

• can't say unless we know how big the force is

Tags

NGSS.HS-PS2-1

Which requires more work – a person walking up stairs or a person running up stairs?

• walking

• running

• they require equal work

• no work is required for either because the movement is vertical

Tags

NGSS.MS-PS3-5

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

Tags

NGSS.HS-PS2-1

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