Question

A 1200kg car going 30m/s applies its brakes and skids to rest. If the friction force between sliding tiresband pavement is 600N. How far does the car skids before coming tonrest.

Answer 1

Given:

$v_0=30\:\rm m/s$

$m=1200\:\rm kg$

$F=600\:\rm N$

The energy-work theorem says

$$0-\frac{mv_0^2}{2}=W=-Fd$$

The distance traveled before car coming to the rest

$$d=\frac{mv_0^2}{2F}=\frac{1200*30^2}{2*600}=900\:\rm m$$