Acceleration is measured in velocity change per second, so miles per hour per second (mphps), feet per second per second (fpsps or fps/s) etc. Deceleration is negative acceleration, so I probably won't use that term from here on out and simply stitch with acceleration.
If you are starting from zero with an acceleration of 3 fps/s, your velocity will increase by 3 for every second from then on. So 0, 3, 6, 9, 12 etc.
There is one equation relating velocity(v) and acceleration(a):
Use this equation for any problem with initial and final velocity, and acceleration. Click here to continue reading