The motorcycle, moving at a speed of 72 km / h, began to brake. What path will it take to stop if the friction coefficient is 0.2?

Task data: V0 (the speed with which the motorcycle was moving before the start of braking) = 72 km / h (20 m / s); μ (coefficient of friction) = 0.2.

Reference values: g (acceleration due to gravity) ≈ 10 m / s2.

1) Determine the modulus of acceleration of the motorcycle during braking from the equality: m * a = Ftr. = μ * N = μ * m * g, whence a = μ * g = 0.2 * 10 = 2 m / s2.

2) We calculate the path of the motorcycle to the stop: S = V0 ^ 2 / 2a = 20 ^ 2 / (2 * 2) = 100 m.

Answer: The motorcycle will travel 100 meters to the stop.