Question

Find the initial velocity of a car which is stopped in 10 seconds by applying brakes.Retardation due to brakes is 2.5 m/s2.

Answer 1

v =u-at
0=u-25/10into10
0=u-25
25=u
intial velocity=25

Answer 2

u-? t-10
v-0
a-(-2.5/s^2)(retardation)
a=(v-u) /t
at=v-u
at-v=-u
-2.5*10-0=-u
-25=-u
25=u