Please solve this question in details.

Determine the smallest mass (in kg) of the man so that he can move the crate. The uniform crate has a mass of mc = 170 kg. The coefficient of static friction between the crate and the floor is us = 0.21. The coefficient of static friction between his shoes and the floor is us' = 0.4. Assume that the man exerts only horizontal force on the crate. Use a = 1.4 m, b =2.5 m, c = 1.5 m, and g = 9.81 m/s2. mc b C a