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 distance travelled by the car after applying the brakes.

Answer 1

Given,

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

we can use here Newton's third law of motion.

$v^2–u^2=2as$

$0^2–{25}^2=2\times (–2.5)\times s\Rightarrow –625=–5\times s\Rightarrow s=125m.$