2. A small ball is projected vertically upwards from ground level with speed \(u \mathrm {~m} \mathrm {~s} ^ { - 1 }\). The ball takes 4 s to return to ground level.
- Draw, in the space below, a velocity-time graph to represent the motion of the ball during the first 4 s .
- The maximum height of the ball above the ground during the first 4 s is 19.6 m . Find the value of \(u\).