a. M*g = 20 * 9.8 = 196 N. = Wt. of crate = Normal(Fn).
Fap-Fs = M*a.
75-Fs = 20*0 = 0, Fs = 75 N. = Force of static friction.
us = Fs/Fn = 75/196 = 0.383.
b. 60-Fk = M*a.
60-Fk = M*0 = 0, Fk = 60 N.
uk = 60/196 = 0.306.
A mover finds that a 20 kg crate initially at rest requires a 75 N horizontal force to set the crate in motion, but only a 60 N force to maintain a constant velocity. Find
a) the co-efficient of static friction between crate and floor.
b) the co-efficient of kinetic friction between crate and floor.
Help ASAP please!!
1 answer