1. The problem statement, all variables and given/known data A crate is sitting on the back of a truck at 20 m/s with a μ of 0.4. With what acceleration can the truck stop without having the crate slide? 2. Relevant equations I'm not sure if I am supposed to use this equation: a = μ(9.8) 3. The attempt at a solution a = 0.4(9.8) = 3.92 m/s^2.