What is the braking distance of a 1000 kg car moving at a speed of 108 km / h, the coefficient

What is the braking distance of a 1000 kg car moving at a speed of 108 km / h, the coefficient of friction between the road and the tires is 0.3.

Given:

m = 1000 kilograms – vehicle weight;

v = 108 km / h = 30 m / s – vehicle speed before braking;

g = 10 m / s ^ 2 – acceleration of gravity;

k = 0.3 is the coefficient of friction between the road and the tires of the vehicle.

It is required to determine the braking distance of the vehicle S (meters).

The friction force acting on the car is equal to:

F = m * g * k = 1000 * 10 * 0.3 = 3000 Newton.

Then the acceleration of deceleration will be equal to:

a = F / m = 3000/1000 = 3 m / s ^ 2.

The braking distance of the car will be equal to:

S = v ^ 2 / (2 * a) = 30 ^ 2 / (2 * 3) = 900/6 = 150 meters.

Answer: the braking distance of the car will be 150 meters.