15 Questions

Questions and Answers

- 1.Which of the following is not a unit for power?
- A.
Joule – second

- B.
Watt

- C.
Newton-meter per second

- D.
Horsepower

- 2.Car A has a mass of 1000 kg and a speed of 60 km/h, and car B has a mass of 2000 kg and a speed of 30 km/h. The kinetic energy of car A is _____.
- A.
Half that of car B

- B.
Equal that of car B

- C.
Twice that of car B

- D.
Four times that of car B

- 3.If an object has kinetic energy, then it also must have _____.
- A.
Speed

- B.
Impulse

- C.
Acceleration

- D.
Force

- 4.A feather and a coin are dropped in the air. Each falls with equal _____.
- A.
Momenta

- B.
Kinetic energies

- C.
Potential energy

- D.
None of the above

- 5.When a bullet is fired from a rifle, the force on the rifle is equal to the force on the bullet. However, the energy of the bullet is greater than the energy of the recoiling rifle because the _______.
- A.
Force on the bullet acts for a longer distance

- B.
Bullet's momentum is greater than that of the rifle

- C.
Force on the bullet acts for a longer time

- D.
The impulse of the bullet is more

- 6.An object that has kinetic energy must be _____.
- A.
Moving.

- B.
Falling.

- C.
At an elevated position.

- D.
At rest.

- 7.An object that has potential energy has this energy because of its _____.
- A.
Speed.

- B.
Acceleration.

- C.
Momentum.

- D.
Location.

- 8.An object is raised above the ground gaining a certain amount of potential energy. If the same object is raised twice as high it gains _____.
- A.
Four times as much potential energy.

- B.
Twice as much potential energy.

- C.
Half as much potential energy

- D.
Neither of these.

- 9.When an object is lifted 10 meters, it gains a certain amount of potential energy. If the same object is lifted 20 meters, its potential energy is ______.
- A.
Less.

- B.
The same

- C.
Twice as much.

- D.
Four times as much

- 10.Two identical arrows, one with twice the kinetic energy of the other, are fired into a hay bale. The faster arrow will penetrate _____.
- A.
The same distance as the slower arrow.

- B.
Twice as far as the slower arrow.

- C.
Four times as far as the slower arrow.

- D.
More than four times as far as the slower arrow.

- 11.A ball is projected into the air with 100 J of kinetic energy which is transformed to gravitational potential energy at the top of its trajectory. When it returns to its original level after encountering air resistance, its kinetic energy is _____.
- A.
Less than 100 J.

- B.
More than 100 J.

- C.
100 J.

- D.
Not enough information given.

- 12.Strictly speaking, a car will burn more gasoline if the car radio is turned on. This statement is _____.
- A.
Totally false.

- B.
True only if the car's engine is running.

- C.
True only if the car's engine is stopped.

- D.
Always true.

- 13.Two identical arrows, one with twice the speed of the other, are fired into a hay bale. The faster arrow will penetrate _____.
- A.
The same distance as the slower arrow.

- B.
Twice as far as the slower arrow.

- C.
Four times as far as the slower arrow.

- D.
More than four times as far as the slower arrow.

- 14.How many Joules of energy are in one kilowatt-hour?
- A.
1 J

- B.
60 J

- C.
60 kilojoules

- D.
3.6 megajoules

- 15.A feather and a coin dropped in a vacuum fall with equal _____.
- A.
Forces

- B.
Momenta

- C.
Accelerations

- D.
Kinetic energies