1.1. A person throws an object vertically upwards from the top of a platform. Figure 1 shows a displacement-time graph for the motion of the object until it lands on the ground below the platform.

At time $t$ seconds the displacement of the object is $s$ metres.

Given that the equation of the graph can be written as

$s=At(B−t)$

where $A$ and $B$ are integers, use Figure 1 to determine the values of $A$ and $B$.

1.2. Determine the maximum height above the platform that the object reaches.

1.3. Find

(i) the average velocity of the pebble,

(ii) the average speed of the pebble.