Work, Energy Power

A roller coaster whose average speed is 32 m/s is at the top of a 72m hill and weighs 966N. At the top of the hill the coaster car has ___________________ energy.

• only kinetic energy

• only potential energy

• mostly kinetic energy

• both kinetic and potential energy

Tags

NGSS.MS-PS3-2

NGSS.MS-PS3-4

NGSS.MS-PS3-5

What is the potential energy of a 3kg ball that is on the ground?

• 0 J

• 3 J

• 9.8 J

• 29.4 J

Tags

NGSS.MS-PS3-2

A weightlifter holds a 100 kg barbell above her head. Is work done?

• Yes because there is a force applied to the barbell and the force causes a displacement of the barbell.

• Yes because there is an upward force applied to the barbell and the barbell moves vertically.

• No because no displacement occurred.

• No because there is no force applied.

A 735kg empty roller coaster is at its starting point whose distance from the ground is 150m. After a while, it moves at point B whose distance from the ground is 120m. What is the kinetic energy of the coaster at point B?

• 1,080,450J

• 864,360J

• 216,090J

• 0J

Tags

NGSS.MS-PS3-1

Which of the following is defined as an energy transfer?

• kinetic energy

• work

• potential energy

• chemical energy

Tags

NGSS.MS-PS3-3

NGSS.MS-PS3-4

NGSS.MS-PS3-5

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.MS-PS2-2

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Four students run up the stairs in the time shown. Which student has the largest power output?

• A

• B

• C

• D

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

A major league pitcher can throw a baseball with a kinetic energy of 150 J. How much work must the pitcher do to the ball to give it that much KE?

• 150 J

• 0

• Can’t tell without knowing the mass of the ball

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-4

NGSS.MS-PS3-5

What is the unit for power?

• what

• watt

• joule

• Jewel-Osco

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