Question

A bus travelling with an uniform velocity of 40 m/s

suddenly applies brakes, such that it’s velocity decreases to

20 m/s within 5 s. Calculate :- (3)

I) Retardation produced in the bus after application of

brake.

II) Distance travelled by the bus in that 5 s time interval.​

Answer 1

Answer:

In the given question

u=20m/s

v=0m/s

t=10s

and a=?

we know the formula v =u + at

so putting the values we get

0 = 20 + a X 10

- 20 = 10 a

-2 = a

we get acceleration is -2 so retardation will be +2 m/ sec sq.

Answer 2

4m/s^2;150m

Explanation:

I)uniform velocity (u)=40m/s

final velocity (v)=20m/s

as we know,

v=u-at(-ve because retardation)

20=40-5a

=>5a=40-20

=>5a=20

=>a=4

so retardation a=4m/s^2

II)Again we know

V^2=u^2+2as

20^2=40^2-2.4.s

8s=1600-400

8s=1200

s=1200/8

s=150

Distance traveled by the bus in that 5s time travel is 150 m