posted by kevin .
A 1,040-N crate is being pushed across a level floor at a constant speed by a force of 350 N at an angle of 20.0° below the horizontal;
(a) What is the coefficient of kinetic friction between the crate and the floor?
(b) If the 350-N force is instead pulling the block at an angle of 20.0° above the horizontal, what will be the acceleration of the crate? Assume that the coefficient of friction is the same as that found in part (a).