Question

20. Brakes are applied to a car travelling at 30 m s-1. Its velocity
is reduced to 20 ms-1 in 5 seconds. Calculate the retardation
produced by the brakes. Also calculate the distance covered
in those 5 seconds.(H.P.S.S.C.E. 2010)[Ans. 2 m s-2, 125 m)
21. A body starts from rest and acquire un​

Answer 1

retardation=v-u/t=30-20/5= 2ms-2.

distance covered s=v²-u²/2a

400-900/2(-2)=125 m