Question

A truck is brought to rest within 20 second by applying brakes.find tge initial velocity ,if the retardation due to brakes in 2 m/s²

Answer 1

Hi friend,

u=? , v=0 , t=20sec , a= -2m/s²
We know that,
a=v-u/t
(-2)=(0-u)/20
(-2)=-u/20
2=u/20
u=2×20=40 m/s
Therefore, Initial velocity= 40m/s... ANSWER..

HOPE THIS HELPS YOU:-))

Answer 2

Final velocity(v)=0m/s
Time(t)=20sec
Acceleration(a)=-2m/s²
According to first equation of motion
v=u+at
0=u+(-2)*20
0=u-40
u=40m/s



Hope this helps....