Exercise – Uniformly Accelerated Motion

The reaction distance s_react represents a uniform, straight-line movement:
s_react = v₀ ∙ t_react = 50 km/h ∙ 1s = 13,89 m/s ∙ 1s = 13,89 m

  ( 50km/h = 50 000 m / 3600 s = 13,89 m/s )

The braking distance s_braking can be determined by a negatively accelerated movement:

To use this equation, you must know that the braking distance must be calculated at the point in time at which the velocity has reached the value 0 m/s. We started with a speed of 13.89 m/s. Thus follows:

v² - v₀² = (0 m/s )² - (13,89 m/s)² = - (13,89 m/s)²

The total stopping distance is the sum of the reaction distance and the braking distance:

s_total = s_react + s_braking = 13,89 m + 12,06 m = 25,95 m