The time required to stop a car of mass 800 kg, moving at a speed of 20 `ms^(-1)` over a distance of 25 m is

Options

A. 2 s
B. `2.5s`
C. 4 s
D. `4.5` s

Answer

C

Explanation

Given, `u=0 ms^(-1),v=20 ms^(-1)`
Mass of car = 800 kg, s = 25 m
We know that, distance covered,
`s=((u+v)/(2))t`,
`rArr25=((0+20)/(2))t`
`=25/(10)=2.5s`