Gravitation Questions And Answers.

1.In which of the following the momentum and energy of each body not conserved?
A. Inelastic collision
B. Oblique collision
C. Elastic collision
D. Head on collision

2.In an elastic collision of two billiard balls, the total kinetic energy is conserved?
A. Completely
B. For a short duration
C. For a long duration but not completely
D. None of Above

3.Which of the following is an example for a force which does work on a body but fails to change its kinetic energy?
A. A body pulled through a plain surface
B. A body pulled through a vertical surface
C. A body pulled through a horizontal surface
D. A body at rest

4.Two masses of 1g and 4g are moving with equal kinetic energy. The ratio of the magnitudes of their momenta is?
A. 4:1
B. √2:1
C. 1:2
D. 1:16

5.If a machine is lubricated with oil?
A. The mechanical advantage of the machine increases
B. The mechanical efficiency of the machine increases
C. Both its mechanical advantage and efficiency increases
D. Its efficiency increases, but its mechanical advantage decreases