Momentum & Impulse (Edexcel A Level Physics): Exam Questions

A student investigated impulse using a trolley fitted with a force sensor. The trolley was pushed towards a fixed spring buffer on a horizontal track. The trolley collided with the buffer and rebounded.

The force sensor recorded the force acting on the trolley during the collision. The graph shows the variation of force with time.

Determine the impulse of the force acting on the trolley during the collision.

Show that the change in velocity of the trolley due to this impulse is about $3{\text{ m s}}^{-1}$.

mass of trolley = $0.85\text{ kg}$

Light gates were used to measure the speed of the trolley before and after the collision.

Deduce whether the light-gate measurements are consistent with the change in velocity shown in (b).

speed of trolley before the collision = $2.60{\text{ m s}}^{-1}$

speed of trolley after the collision = $0.55{\text{ m s}}^{-1}$

The student replaced the spring buffer with a stiffer spring and repeated the experiment. The impulse of the force on the trolley was unchanged.

Explain the effect on the maximum force acting on the trolley.