Question

A car is traveling at 10 m/s. The driver sees a deer jump into the road so he slams on his brakes and the car skids to a stop. If the car stops over a distance of 49 m and the mass of the car and driver is 1,800 kg, what is the friction force between the tires and the road?

Answer 1

Answer:

1836 N

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration

Equation of motion

$v^2-u^2=2as\\\Rightarrow a=\frac{v^2-u^2}{2s}\\\Rightarrow a=\frac{0^2-10^2}{2\times 49}\\\Rightarrow a=-1.02\ m/s^2$

$F=ma\\\Rightarrow F=1800\times 1.02\\\Rightarrow F=1836\ N$

The frictional force provided by the brakes is 1836 N