3. A racing car is travelling on a straight horizontal road. Its initial speed is \(25 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) and it accelerates for 4 s to reach a speed of \(V \mathrm {~m} \mathrm {~s} ^ { - 1 }\). It then travels at a constant speed of \(V \mathrm {~m} \mathrm {~s} ^ { - 1 }\) for a further 8 s . The total distance travelled by the car during this 12 s period is 600 m .

1. Sketch a speed-time graph to illustrate the motion of the car during this 12 s period.
2. Find the value of \(V\).
3. Find the acceleration of the car during the initial 4 s period.