5. Two cars \(P\) and \(Q\) are moving in the same direction along the same straight horizontal road. Car \(P\) is moving with constant speed \(25 \mathrm {~m} \mathrm {~s} ^ { - 1 }\). At time \(t = 0 , P\) overtakes \(Q\) which is moving with constant speed \(20 \mathrm {~m} \mathrm {~s} ^ { - 1 }\). From \(t = T\) seconds, P decelerates uniformly, coming to rest at a point \(X\) which is 800 m from the point where \(P\) overtook \(Q\). From \(t = 25 \mathrm {~s}\), \(Q\) decelerates uniformly, coming to rest at the same point \(X\) at the same instant as \(P\).

1. Sketch, on the same axes, the speed-time graphs of the two cars for the period from \(t = 0\) to the time when they both come to rest at the point \(X\).
2. Find the value of \(T\).