Question

A car travels with a uniform velocity of $25m{s}^{-1}$ for $5s$ the brakes are then applied and the car is uniformly retarded and comes to rest in further $10s$ find the retardation

Answer 1

Given,

$Velocity=25m/s,t=10s$

According to Newton's first law, we can write

$a=\frac{(v–u)}{t}=\frac{(0–25)}{10}=–2.5m/s^2$

Here $–ve$ sign indicates that the acceleration is in opposite direction to the motion of the body.

That is, it is retardation.