Question

Consider a car moving on a straight road with a speed of `100m//s`. The distance at which car can be stopped is `[mu_k=0.5]`
A. `100 m`
B. `400 m`
C. `800 m`
D. `1000 m`

Answer 1

Correct Answer - D
`f = mu_(k) N = mu_(k) mg = ma rArr a = mu_(k) g = 0.5 xx 10 = 5 m//s^(2)`
`v^(2) = u^(2) - 2as rArr 0 = (100)^(2) - 2 xx 5 s rArr s = 1000 m`