1. The problem statement, all variables and given/known data A car level on ground, starting from 15m/s, decelerates uniformly to rest in 20 seconds. What distance does the car cover while decelerating? 2. Relevant equations Vf = Vi+at Vf^2=Vi^2+2aX X=Vit+(1/2)at^2 X = Distance Vf = Final velocity Vi = Initial velocity a = acceleration t = time 3. The attempt at a solution I started with the X=Vit+(1/2)at^2 formula and attempted to plug in the numbers but I have no idea how to find acceleration. I mean, I know acceleration is Δv over Δt but how am I supposed to find the final velocity when I need the acceleration to plug in the formula? I'll admit I zoned out a little in my last class because I was tired from work the day before.