Answer the questions that follow.
(a) (a) Starting from the definition of momentum, derive an expression that relates the net external force F acting on a body of mass m to its initial velocity u, final velocity v, and the time interval t over which the change occurs.
(b) (b) A 0.020kg bullet enters a stationary wooden block with a velocity of 300ms−1 and is brought to rest after penetrating 0.10m into the block. Assuming the deceleration of the bullet is uniform, calculate:
(c) (i) the magnitude of the deceleration of the bullet,
(d) (ii) the average resistive force exerted by the block on the bullet,
(e) (iii) the time taken for the bullet to come to rest once inside the block.
(f) (c) State the magnitude and direction of the force exerted by the bullet on the block, and justify your answer using Newton’s Third Law.