calculating constant deceleration with time

Question

The distance between point A and B is 500m, an object is moving at 50m/s, the object will stop exactly at 500m when it's deceleration reaches zero after 5 seconds, the deceleration is constant, how do I calculate the deceleration?

Answer 1

If the deceleration is constant, then you cam calculate it easily: $$d=-\frac{\Delta v}{\Delta t}$$ Where $\Delta v$ is the change of speed: $$\Delta v=v_{final}-v_{initial}$$ and $\Delta t$ is the change of time (the duration of deceleration): $$\Delta t=t_{final}-t_{initial}$$