Question

A driver applies the brakes on seeing traffic signal 400 m ahead. At the time of applying the brakes the vehicle was moving with 15ms^–1 and retarding with 0.3 ms^–2. The distance of the vehicle after 1 minute from the traffic light is 

(a) 25 m 

(b) 375m 

(c) 360m 

(d) 40 m

Answer 1

Correct option (a)

Explanation:

The maximum distance covered by the vehicle before coming to rest 

= v²/2a = (15)²/(2 x 0.3) = 375

The corresponding time = t v/a = 15/03 = 50sec.

Therefore after 50 sec, the distance covered by the vehicle = 375 m, from the instant of beginning of braking.

The distance of the vehicle from the traffic signal after one minute = (400 – 375) m = 25m.