9709 P42 - Mar 2022 - Q6
3722
A cyclist starts from rest at a fixed point O and moves in a straight line, before coming to rest k seconds later. The acceleration of the cyclist at time t seconds after leaving O is a m/s2, where a = 2t - \frac{3}{5}t^2 for 0 < t \leq k.
- Find the value of k.
- Find the maximum speed of the cyclist.
- Find an expression for the displacement from O in terms of t. Hence find the total distance travelled by the cyclist from the time at which she reaches her maximum speed until she comes to rest.
