A car moving with a speed of 40 km/h can be stopped by applying brakes after 2m, if the same car is moving with a speed of 80 km/h. what is the minimum stopping distance.
(1) 8m
(2) 6m
(3) 4m
(4) 2m
Answer is (1) 8m
ν2 = u2 - 2as.
Or = u2/2a = mu2/2F or ∝ u2
S1/S2 = (u1/u2)2.
Or 2/S2= (1/4)S2 = 8 m
