6 Work and Energy Retest

A weightlifter lifts a 2000 Newton barbell a distance of 1.5 meters. If he generated 800 watts of power, how much time did he spend lifting it?

• 3.75 seconds

• 0.6 seconds

• 1.4 seconds

• 0.3 seconds

Tags

NGSS.HS-PS3-1

As a heavy metal ball rolls down a hill, it goes faster and faster. Which statement is true?

• The ball is gaining potential energy from the hill

• The ball’s potential energy is changing to kinetic energy

• The ball’s kinetic energy is changing into potential energy

• The ball is rapidly losing kinetic energy as it rolls down the hill

Tags

NGSS.MS-PS3-5

What is the maximum distance that a 120 watt motor may vertically lift a 100 Newton weight in 10 seconds?

• 2.3

• 5

• 12

• 1200

The diagram shows a cart at four positions as it moves along its track. At which positions is the sum of the potential energy and kinetic energy of the cart the same?

• W and X only

• X and Y only

• W and Z only

• All positions W through Z

Tags

NGSS.HS-PS3-1

A 3 kg brick falls to the ground from a 6 meter high roof. What is the approximate kinetic energy of the brick just before it touches the ground?

• 2 J

• 176.4 J

• 18 J

• 0.5 J

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

A skateboarder travels from location A to location G as shown above. At which location does the skateboarder have the most kinetic energy and the least potential energy?

• A

• C

• D

• E

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-2

NGSS.MS-PS3-5

Three different boxes are lifted to different heights.

1. Box X weighs 100 N and is lifted to 15 m

2. Box Y weighs 200 N and is lifted to 10 m

3. Box Z weighs 300 N and is lifted to 5 m

Which of the following statements best describes the boxes’ changes in potential energy?

• Boxes X and Y had the same change in potential energy

• Boxes Y and Z had the same change in potenial energy

• Boxes X and Z had the same change in potential energy

• Box X had the greatest change in potential energy

Tags

NGSS.MS-PS2-4

NGSS.MS-PS3-2

A 6.00 kg toy falls from a height of 10.00 m.  What will the kinetic energy of the toy be just before the toy hits the ground? (Assume no air resistance and that g = 9.8 m/s² .

• 60 J

• 588 J

• 1.67 J

• .67 J

Tags

NGSS.HS-PS3-1

The kinetic energy of an object increases as its ____ increases.

• gravitational energy

• potential energy

• specific heat

• velocity

Along which path(s), does a person gain the greatest amount of gravitational potential energy from start to finish?

• A only

• B only

• C only

• The gain is the same along all paths

Tags

NGSS.HS-PS2-4