# What is the stopping distance of a car traveling at 100 km / h on a dry road?

To determine the braking distance of a car at a speed of 100 km / h on dry asphalt, we use the formula:

S = V ^ 2 / 2mg,

where V is the speed of the vehicle (it is represented in the formula in m / s), m is the coefficient of adhesion to the road surface, g is the acceleration.

The adhesion coefficient with dry asphalt is taken as m = 0.7, acceleration g = 9.8 m / s, speed V = 100 km / h = 27.8 m / s. Let’s substitute these values into the formula:

S = (27.8) ^ 2/2 * 0.7 * 9.8 = 772.84 / 13.72 = 56.3 meters.

Thus, the braking distance of the car at a speed of 100 km / h on dry asphalt will be 56.3 meters.

You can check the resulting braking distance using the formula:

S = Ke * V * V / (254 * Фc), where Ke is the braking coefficient, for passenger cars it is equal to one, V is the vehicle speed (in km / h), Фs is the coefficient of adhesion to the coating (for dry coatings 0, 7).

S = 1 * 100 * 100/254 * 0.7 = 56.3 meters.

Answer: The stopping distance will be 56.3 meters.