This diagram shows two identical objects about to make a head-on collision. The objects stick together during the collision. Determine the final speed of the objects. State the direction in which they move.

(a) Explain what is meant by an:

(i) Elastic collision

(a) Explain what is meant by an:

(ii) Inelastic collision

A car of mass $1100 \mathrm{kg}$ is travelling at $24 \mathrm{m}{ \mathrm{s}}^{-1}$. The driver applies the brakes and the car decelerates uniformly and comes to rest in $20 \mathrm{s}$.

(a) Calculate the change in momentum of the car.

A car of mass $1100 \mathrm{kg}$ is travelling at $24 \mathrm{m}{ \mathrm{s}}^{-1}$. The driver applies the brakes and the car decelerates uniformly and comes to rest in $20 \mathrm{s}$.Calculate the braking force on the car.

(c) A car of mass $1100 \mathrm{kg}$ is travelling at $24 \mathrm{m}{ \mathrm{s}}^{-1}$. The driver applies the brakes and the car decelerates uniformly and comes to rest. Determine the braking distance of the car.

A marble of mass $100 \mathrm{g}$ is moving at a speed of $0.40 \mathrm{m}{ \mathrm{s}}^{-1}$ in the $x$ -direction.

 Calculate the marble's momentum. The marble strikes a second, identical marble. Each moves off at an angle of $45°$ to the $x$ -direction.