A parachutist of mass 50.0 kg jumps out of an airplane at a height of 1 040 m. The parachute deploys, and she lands on the ground with a speed of 4.0 m /s. How much energy was lost to air friction during this jump?
a. 4.0E+2 J
b. 8.2E+4 J
c. 4.3E+5 J
d. 5.1E+5 J
e. 6.4E+5 J
[Ques. 2] I drop a 55-g golf ball from 2.50 m high. It rebounds to 1.65 m. How much energy is lost?
a. 0.46 J
b. 4.6 J
c. 0.51 J
d. 0.41 J
e. 0
[Ques. 3] A pile driver drives a post into the ground. The mass of the pile driver is 2 600 kg and it is dropped through a height of 9.0 m on each stroke. If the resisting force of the ground is 4.0 106 N, how far is the post driven in on each stroke?
a. 9.2E+1 cm
b. 5.9E3 cm
c. 7.1E4 cm
d. 5.7E2 cm
[Ques. 4] Preston pushes a wheelbarrow weighing 480 N to the top of a 45.0-m ramp, inclined at 22.0 with the horizontal, and leaves it. Tamara accidentally bumps the wheelbarrow. It slides back down the ramp, during which an 85.0-N frictional force acts on it over the 45.0 m. What is the wheelbarrow's kinetic energy at the bottom at of the ramp? (g = 9.8 m/s2)
a. 1.4E+3 J
b. 1.6E+4 J
c. 1.2E+4 J
d. 8.1E+3 J
e. 4.3E+3 J
[Ques. 5] Adisa pulls a 35.0-N crate up a 4.00-m-long inclined plane at a constant velocity. If the plane is inclined at an angle of 39.0 to the horizontal and there is a constant force of friction of 13.0 N between the crate and the surface, what is the net change in potential energy of the crate?
a. 88 J
b. 88 J
c. 109 J
d. 109 J
e. None of these
[Ques. 6] A 35.0-N crate is pulled up a 4.0-m inclined plane by a worker at constant velocity. If the plane is inclined at an angle of 37 to the horizontal and there exists a constant frictional force of 25.0 N between the crate and the surface, what is the force applied by the worker?
a. zero
b. 3.95 N
c. 21.1 N
d. 46.1 N
e. 84.2 N
[Ques. 7] A Hooke's law spring is mounted horizontally over a frictionless surface. The spring is then compressed a distance d and is used to launch a mass m along the frictionless surface. What compression of the spring would result in the mass attaining 4 times the speed received in the situation described here?
a. 2.00d
b. 0.50d
c. 4.00d
d. 16.00d
[Ques. 8] A Hooke's law spring is compressed 14.6 cm from equilibrium, and the potential energy stored is 76.0 J. What compression (as measured from equilibrium) would result in 100 J being stored in this case?
a. 11.8 cm
b. 16.7 cm
c. 43.8 cm
d. 33.5 cm
e. No answer is correct.
[Ques. 9] When a Hooke's law spring is stretched a distance 3x, how much is the increase in energy stored in it from when it was stretched a distance x? Give your answer in terms of a multiple of the energy stored in the spring when it is stretched a distance x.
a. It is 3 times as much. b. It is 8 times as much.
c. It is 4 times as much. d. It is 9 times as much.
[Ques. 10] A Hooke's law spring is mounted horizontally over a frictionless surface. The spring is then compressed a distance d and is used to launch a mass m along the frictionless surface. What compression of the spring would result in the mass attaining double the kinetic energy received in the above situation?
a. 1.41d
b. 1.73d
c. 2.00d
d. 4.00d
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