2 A train of mass 20,000 kg is travelling along a horizontal surface at 35 ms-1 when the driver sees a man tied to the tracks ahead, disengages the engine and applies the brakes. When braking the total resistive force on the train is (4000 + 500v) N, where v is the speed of the train. How far does the train travel before coming to rest?

2 A train of mass 20,000 kg is travelling along a horizontal surface at 35 ms-1 when the driver sees a man tied to the tracks ahead, disengages the engine and applies the brakes. When braking the total resistive force on the train is (4000 + 500v) N, where v is the speed of the train. How far does the train travel before coming to rest?