With what acceleration did the body move during emergency braking, if its stopping distance

With what acceleration did the body move during emergency braking, if its stopping distance is 500 meters, and the initial speed is 20 m / s.

Task data: S (stopping distance of a given body) = 500 m; V0 (speed before emergency braking) = 20 m / s.

The desired acceleration during emergency braking is expressed from the formula: S = (V ^ 2 – V0 ^ 2) / 2a, whence a = (V ^ 2 – V0 ^ 2) / 2S.

Let’s perform the calculation: a = (0 ^ 2 – 20 ^ 2) / (2 * 500) = -0.4 m / s2.

Answer: During emergency braking, a given body moved with an acceleration of -0.4 m / s2.