AP Energy

Two objects, one of mass m and the other of mass 2m, are dropped from the top of a building. If there is no air resistance, when they hit the ground _______.

• the heavier one will have half the kinetic energy of the lighter one

• the heavier one will have twice the kinetic energy of the lighter one

• the heavier one will have one-fourth the kinetic energy of the lighter one

• the heavier one will have four times the kinetic energy of the lighter one

Tags

NGSS.HS-PS2-4

NGSS.HS-PS3-1

NGSS.HS-PS3-2

A 30 N box is pulled upward 6.0 m along the surface of a ramp that rises at 37° above the horizontal. How much work does gravity do on the box during the process?

• -140 J

• 140 J

• -180 J

• 180 J

What is the net power needed to change the speed of a 1600 kg sport utility vehicle from 15.0 m/s to 40.0 m/s in 4.00 seconds?

• 300,000 W

• 275,000 W

• 125,000 W

• 140,000 W

A person carries a 25.0 N rock through the path shown in the figure, starting at point A and ending at point B. The total time from A to B is 1.50 minutes. How much work did gravity do on the rock between A and B?

• 20 J

• 75 J

• 275 J

• 0 J

Linda does four times as much work as James does and in one-third the time. Linda’s power output is ________.

• four times James’ power output

• one-third as much as James’ power output

• twelve times James’ power output

• the same as James’ power output

A truck has twice the mass of a car and is moving 1.5 times faster than the car. If Kt and Kc refer to the kinetic energies of the truck and car respectively, it is correct to say that

• Kt = 4.5Kc

• Kt = 2Kc

• Kt = 0.5Kc

• Kt = 16Kc

How much work is required to stretch an ideal spring of spring constant 65 N/m from x = 0.10 m to x = 0.25 m if the unstretched position is at x = 0.00 m?

• 0.73 J

• 1.71 J

• 3.45 J

• -0.73 J

A 30 N stone is dropped from a height of 10 m and strikes the ground with a speed of 13 m/s. What average force of air friction acted on the stone as it fell?

• 130 N

• 2.9 N

• 4.7 N

• 7.3 N

Work is _____.

• the ability to use energy

• a transfer of energy

• energy

• the rate of power expended

Work is _____.

• a scalar

• a vector

• both a scalar and vector

• neither a scalar nor vector