These are the speed-time graphs for two falling balls:

Determine the terminal velocity of the plastic ball.

These are the speed-time graphs for two falling balls:

Both balls are of the same size and shape but the metal ball has a greater mass. Explain, in terms of Newton's laws of motion and the forces involved, why the plastic ball reaches a constant velocity, but the metal ball does not.

These are the speed-time graphs for two falling balls:

Explain why both balls have the same initial acceleration. 

A car of mass $1200 \mathrm{kg}$ accelerates from rest to a speed of $8.0{ \mathrm{m} \mathrm{s}}^{-1}$ in a time of $2.0 \mathrm{s}$. At high speeds the resistive frictional force $\mathrm{F}$ produced by air on a body moving with velocity $\mathrm{v}$ is given by the equation $\mathrm{F}={\mathrm{bv}}^2$, where $\mathrm{b}$ is a constant. Derive the base units of force in the SI system.

A car of mass $1200 \mathrm{kg}$ accelerates from rest to a speed of $8.0{ \mathrm{ms}}^{-1}$ in a time of $2.0 \mathrm{s}$.

(b) At high speeds the resistive frictional force $\mathrm{F}$ produced by air on a body moving with velocity $\mathrm{v}$ is given by the equation $\mathrm{F}={\mathrm{bv}}^2$, where $\mathrm{b}$ is a constant.

(ii) Determine the base units of $\mathrm{b}$ in the SI system.

State the difference between the base units of mass and weight in the SI system.

State Newton's second law of motion in terms of acceleration.

 When you jump from a wall on to the ground, it is advisable to bend your knees on landing. State how bending your knees affects the time it takes to stop when hitting the ground.

When you jump from a wall on to the ground, it is advisable to bend your knees on landing. Using Newton's second law of motion, explain why it is sensible to bend your knees.