A bicycle weighing 20 kg moves at a speed of 15 km / h. Calculate the braking distance

A bicycle weighing 20 kg moves at a speed of 15 km / h. Calculate the braking distance if the coefficient of tire-to-road friction is 0.2.

Initial data: m (cyclist’s weight) = 20 kg; Vн (the speed with which the cyclist moved) = 15 km / h (4.17 m / s); μ (coefficient of friction of bicycle tires on the road surface) = 0.2.

Reference data: g (acceleration due to gravity) = 9.81 m / s2

1) Determine the acceleration of the cyclist during braking: m * a = μ * m * g, whence a = μ * g = 0.2 * 9.81 = 1.962 m / s2.

2) Calculate the braking distance: S = Vn ^ 2 / 2a = 4.17 ^ 2 / (2 * 1.96 ^ 2) = 4.43 m.

Answer: The braking distance of the cyclist is 4.43 m.