Question

A car moving with the speed 50 km/ he can be stopped by brakes after at least 6m. If the same car is moving with the speed of 100 km/hr the minimum stopping distance is

Answer 1

Initial velocity, u = 50 km/h = 50 × (5/18) = 250/18 m/s

Final velocity, v = 0

Distance travelled before coming to rest, s = 6 m

Using, v² = u² + 2as

=> a = -u²/(2s)

=> a = -16.075 m/s²

Again,

u = 100 km/h = 500/18 m/s

v = 0

a = -16.075 m/s²

Now, v² = u² + 2as

=> s = -u²/(2a) = 24 m