5. A racing car is moving along a straight horizontal track with constant acceleration. There are three checkpoints, \(P , Q\) and \(R\), on the track, where \(P Q = 48 \mathrm {~m}\) and \(Q R = 200 \mathrm {~m}\). The car takes 3 s to travel from \(P\) to \(Q\) and 5 s to travel from \(Q\) to \(R\). Find

1. the acceleration of the car,
2. the speed of the car as it passes \(P\).