Energy, Work, and Power

An object has 12.4 J of potential energy and 23.5 J of kinetic energy. What is the mechanical energy of the system?

• 11.1 J

• 1.895 J

• 35.9 J

• 291.4 J

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

What is the kinetic energy of an 9 kg bowling ball rolling at 3.30 m/s?

• 29.7 J

• 323.4 J

• 49.005 J

• 14.85 J

Tags

NGSS.MS-PS3-1

An 80 kg skier stands at the top of a 40 meter slope. What is her gravitational potential energy before she skies down the slope?

• 3200 J

• 31,360 J

• 15,680 J

• 19.6 J

Tags

NGSS.HS-PS2-4

If you hold a 20 N object 2 m off of the ground, how much work have you done?

• 40 J of Work

• 10 J of Work

• No Work

• 18 J of Work

If you drive your 1,000 kg car from sea level up to the Nu'uanu Pali lookout, which is 366 m above sea level, how much will you have increased your car's gravitational potential energy?

• 3,000,000 J

• 366,000 J

• 3,586,800 J

• 586,800 J

What is the kinetic energy of a 4 kg rock falling through the air at 5 m/s?

• 10 J

• 50 J

• 20 J

• 200 J

Tags

NGSS.MS-PS3-1

If a rock falls from a cliff, at what point are its kinetic energy and its potential energy the same? Ignore air resistance.

• Just as it starts to fall

• just before it hits the bottom

• halfway down

• never

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

If two rocks are launched through the air at the same speed, but one has twice as much mass as the other, how do their kinetic energies compare?

• The kinetic energy of the two rocks is the same because they have the same speed

• The rock with the greater mass will only move a small distance and then fall straight to the ground

• The two rock could not have the same speed if they have different masses

• The rock with the greater mass has more kinetic energy than the rock with less mass even though they are traveling at the same speeds because both mass and speed affect kinetic energy.

Tags

NGSS.MS-PS3-1

Where would a car traveling on a roller coaster track have the most potential energy?

• At the bottom

• Halfway to the top

• at the top

• halfway to the bottom

• It is always the same

Tags

NGSS.MS-PS3-2

If a 2 kg ball is traveling at 4 meters per second, what is its kinetic energy?

• 1 J

• 2 J

• 4 J

• 8 J

• 16 J

Tags

NGSS.MS-PS3-1