How calculate distance if you are given velocity and deceleration?

Answer 1

First you must know the initial velocity, the acceleration, and the time it takes to reach 0 velocity.

Use this equation: d=Vi+(at²)/2, where Vi is initial velocity, a is acceleration, and t is time.

Here is an example, let's say

Vi=25 m/s

Vf=0

a=-10m/s/s

t=1.7s

d=25+[-10(1.7²)/2] -> 1.7² = 2.89 -> -10(2.89)=-28.9 -> -28.9/2=-14.45

d=25+(-14.45)

d=10.55

Therefore, the object traveled 10.55m before stopping.

Also, sorry for not including units in the example; it would have been messy :P

And the -> between parts in the equation is me trying to make arrows to separate my work, in case that confused you.

Answer 2

Velocity is distance over time, and acceleration is change in velocity over time. You can get the time by dividing deceleration by velocity (of course, taking the absolute value). From there, velocity equals distance over time. Distance is velocity * time.