Consider, a car moving along a straight horizontal road with a speed of 72 km/h. If the coefficient of static friction between the tyre and the road is 0.5, the shortest distance in which the car can be stopped is (Take `g=10 //s^(2)`)

Options

A. 30 m
B. 40 m
C. 72 m
D. 20 m

Answer

b

Explanation

`a = mu R//m = mug = 0.5 xx 10 = 5ms^(-2)`
`s = v^(2)-u^(2)//2a = 0-20^(2)//2 (-5) = 40` m