Question

A bus is running with a velocity of 72km/h .On seeing a boy on the road 65m a head ,the driver jammed on the brakes and the bus stopped with uniform retardation 5m/s2 . calculate the distance traveled by the bus and discuss whether the accident took place or not?

Answer 1

Explanation:

Now we know that initial velocity of bus is = 72 km/h

so in m/s = 72÷ 3.6 = 20 m/s

now we have quantities

V = 0 m/s

U = 20 m/s

a ( retardation) = -5 m/s^2

so lets find out time

V = U + at

0 = 20 + (-5m/s^2 (t) )

-20 = - 5m/s^ 2 (t)

t = -20 / - 5 = 4 sec

now we have time as 4 sec

so lets find distance travelled by bus

S = ut + (a(t)^2)×(0.5)

S = 20 ( 4) + ( -5 ( 4)^2) × ( 0.5)

S = 80 + ( - 40)

S = 40 m

So the distance covered will be 40 m

And accident won't take place in this case as bus

came to rest exactly 25 m before its collision with that boy

hope it was helpful

Answer 2

Explanation:

Now we know that initial velocity of bus is = 72 km/h

so in m/s = 72÷ 3.6 = 20 m/s

now we have quantities

V = 0 m/s

U = 20 m/s

a ( retardation) = -5 m/s^2

so lets find out time

V = U + at

0 = 20 + (-5m/s^2 (t) )

-20 = - 5m/s^ 2 (t)

t = -20 / - 5 = 4 sec

now we have time as 4 sec

so lets find distance travelled by bus

S = ut + (a(t)^2)×(0.5)

S = 20 ( 4) + ( -5 ( 4)^2) × ( 0.5)

S = 80 + ( - 40)

S = 40 m

So the distance covered will be 40 m

And accident won't take place in this case as bus

came to rest exactly 25 m before its collision with that boy