A car moves with constant acceleration along a straight horizontal road. The car passes the point \(A\) with speed \(5 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) and 4 s later it passes the point \(B\), where \(A B = 50 \mathrm {~m}\).
Find the acceleration of the car.
When the car passes the point \(C\), it has speed \(30 \mathrm {~m} \mathrm {~s} ^ { - 1 }\).