physics
posted by help .
The floor of a railroad flatcar is loaded with loose crates having a coefficient of static friction of 0.20 with the floor. If the train is initially moving at a speed of 47 km/h, in how short a distance can the train be stopped at constant acceleration without causing the crates to slide over the floor?
m

F=ma
mu*mg=ma
solve for acceleration.
Now, using
vf^2=vi^2+2ad solve for distance d.