Question

4. A car is travelling at 108 km/h, when the car driver sees a bus 150m ahead on road and put brake. What is the constant magnitude of deceleration is required to stop the car in time to avoid hitting?

Answer 1

Explanation:

Given,

Speed=20m/s,d=50m,retardation=5m/s

2

Let the ppossible reaction time be t

s

So the car moves 20tm And applied breaks with retardation 5m/s

2

So, the total distance under retardation is ≤50m

Thus the distance under the application of retardation = 2×520 2 −0 2 =s ′ ⇒s ′ =40m

Therefore, 20t s

+40≤=50⇒20t s.

≤50−40⇒20t s

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