Question

A vehicle is moving with 100 m/s
driver saw a man caossing the road
at dis-1oo m, what should
be the retardation of car
to prevent accident
Please urgently answer !
​

Answer 1

Answer:

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 =

2×5

20

2

−0

2

=s

′

⇒s

′

=40m

Therefore, 20t

s

+40≤=50⇒20t

s

≤50−40⇒20t

s

=10⇒t

s

≤

2

1

≤0.5s