A railroad car has crates in it with a coefficient of .5 w/ the car's floor. The train is moving at 22m/s, how short a distance can it be stopped w/o letting the crates slide? Fnet = 0 because you don't want sliding. a = coefficient of static friction x gravity When I solved for a, I got 4.9m/s2. I know if I multiply this by the mass of the crates, it should be equal to the static friction force. I think I have to take the derivative of the velocity to get acceleration, and the antiderivative of velocity to get distance, but how do I do this with no other variables?