With what speed did the car move before the start of braking, if it covered 50 m braking distance in 5 s?

To find the speed of a given car before braking, we will use the formula: S = (V + V0) * t / 2, whence V0 = 2S / t – V.

Values of variables: S – braking distance (S = 50 m); t is the duration of inhibition (t = 5 s); V – final speed (V = 0 m / s).

Let’s perform the calculation: V0 = 2S / t – V = 2 * 50/5 – 0 = 20 m / s.

Answer: Before the start of its braking, the given vehicle had a speed of 20 m / s.