物理動量 DSE、CE 選擇題（第 5 頁）

41.

A trolley of mass $1$ kg travelling at $2\ \mathrm{m\,s^{-1}}$ on a smooth horizontal plane has a lump of plasticine dropped from a height $5$ m onto it. If the mass of the plasticine is $2$ kg, the velocity of the loaded trolley will be

42.

A particle is in motion with a constant force acting on it. Which of the following physical quantities will be changing during the time when the force is acting ?

(1)acceleration of the particle

(2)momentum of the particle

(3)kinetic energy of the particle

43.

When a constant unbalanced force is applied to a particle, which of the following will change with time ?

(1)The acceleration of the particle

(2)The momentum of the particle

(3)The kinetic energy of the particle

44.

A ball is dropped from a height $h$ above the ground. Each time it hits the ground, one-half of the original kinetic energy is lost. How high will the ball rise above the ground after the second impact ?

45.

Two objects $P$ and $Q$ of mass $2$ kg and $3$ kg respectively have the same momentum. They are then subjected to the same constant resisting force and gradually brought to rest. What is the ratio of the stopping distance of $P$ to that of $Q$ ?