Question

16. A bus starts from rest with an acceleration of 1 m/sec2. A man who is 48 m behind the bus starts with a uniform velocity of 10 m/sec, then the minimum time after which the man will catch the bus is -
a. 12 sec
b. 8 sec
c. 10 sec
d. 4.8 sec

Answer 1

Explanation:

Let man will catch the bus after time t.Since the distance from man position is same for both at time t

⇒ Distance covered by bus = Distance covered by man -48

⇒

2

1

at

2

=vt−48

⇒

2

1

(1)t

2

=10t−48

⇒t

2

−20t+96=0

⇒(t−12)(t−8)=0

⇒t=8s (minimum value) or t=12s

So,at t=8s,the man will catch the bus