A 1000 kg compact car stops without skidding on asphalt with a coefficient of friction of 0.85. What is the stopping distance of the car if it was originally traveling at 27 m/s?

43.8 m

Explanation:

The only force acting on the car is the frictional force f and since friction is a force that is always directed opposite to the direction of motion, it will have a negative sign. Therefore, we can write Newton's 2nd law as

(1)

(2)

Substituting Eqn(2) into Eqn(1), we get

(3)

To find the stopping distance x, we are going to use the equation

Initially, the car was moving at When it stopped, its final velocity is zero. Using these, as well as Eqn(3) on the equation for v^2, we find that

or solving for x,