Question

(21) A body moving with a velocity of 20 cms-'encounters a retardation
of 5 cm s-2. How far does it move before coming to rest? How long does
this take?​

Answer 1

Explanation:

initial velocity=u=20m/s

a=retardation=5m/s²

it comes to rest so final Velocity

v²=u²-2as

0=20²-2×5×s

10s=400

s=400/10

distance=s=40m

So the distance it travels before coming to rest is 40 metres.

v=u-at

0=20-5t

5t=20

time=t=20/5=4seconds

The time is 4seconds