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.
c. It is 4 times as much.
b. It is 8 times as much.
d. It is 9 times as much.
[Ques. 2] A Carnot engine runs between a hot reservoir at Th and a cold reservoir at Tc. If one of the temperatures is either increased or decreased by 3.5 K, which of the following changes would increase the efficiency by the greatest amount?
a. increasing Th
b. increasing Tc
c. decreasing Tc
d. cannot be determined from information given
[Ques. 3] 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 speed received in the above situation?
a. 1.41d
c. 2.00d
b. 1.73d
d. 4.00d
[Ques. 4] Of the following heat engines, which has the highest efficiency?
a. Hero's engine
c. a car's gasoline engine
b. a Carnot engine
d. a truck's diesel engine
[Ques. 5] 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
c. 2.00d
b. 1.73d
d. 4.00d
[Ques. 6] The Carnot cycle consists of a combination of _____ and _____ processes.
a. isobaric, isovolumetric
c. isobaric, isothermal
b. isovolumetric, adiabatic
d. adiabatic, isothermal
[Ques. 7] A Hooke's law spring is compressed 12.0 cm from equilibrium, and the potential energy stored is 36.0 J. What compression (as measured from equilibrium) would result in 100 J being stored in this case?
a. 20.0 cm
c. 13.6 cm
b. 14.1 cm
d. The correct answer is not given.
[Ques. 8] A gasoline engine with an efficiency of 40.0 operates between a high temperature T1 and a low temperature T2 = 320 K. If this engine operates with Carnot efficiency, what is the high-side temperature T1?
a. 1070 K
c. 533 K
b. 868 K
d. 457 K
[Ques. 9] A Hooke's law spring is compressed 12.0 cm from equilibrium and the potential energy stored is 36.0 J. What is the spring constant in this case?
a. 10,000 N/m
c. 1200 N/m
b. 5000 N/m
d. The correct answer is not given.
[Ques. 10] A 600-MW electric power plant has an efficiency of 30. It loses its waste heat in large cooling towers. Approximately how much waste heat (in MJ) is discharged to the atmosphere per second?
a. 1400 MJ
c. 800 MJ
b. 1900 MJ
d. 560 MJ
Quick Reply
