Question

a car running at 72km/hr and at a distance of 25 mts on applying breaks. calculate the avarage retardation

Answer 1

first u=72×5/18=20m/s
s=25m v=0 (body comes to rest)
a=?
using third equation of motion
v*2-u*2=2 as
0-(20)*2/2s=a
-400/2×25=a
-400/50=a
-8=a
hence retardation is 8m/s*2.

thank you I hope it helps you.

Answer 2

Hi friend,

We know that,

u=72×5/18

=20m/s

s=25m
v=0 (body comes to rest)
a=?
By using third equation of motion,

v*2-u*2=2 as
0-(20)*2/2s=a

-400/2×25=a

-400/50=a

-8=a
hence retardation is 8m/s*2.

Hope it helps you a little!!!