Question

An automobile travelling with a speed of 60 km/h, can brake to stop within a distance of 20 m. If the car is going twice as fast, i.e, 120 km/h, the stopping distance will be

(a) 20 m

(b) 40 m

(c) 60 m

(d) 80 m

Answer 1

Correct option (d) 80 m
Explanation :

The braking retardation will remain same and assumed to be constant, let it be a. From third equation of motion,