Posted by Kris on Saturday, October 20, 2012 at 12:15pm.
Bonnie and Clyde are sliding 500 bank safe across the floor to their getaway car. The safe slides with a constant speed if Clyde pushes from behind with 385 of force while Bonnie pulls forward on a rope with 300 of force.What is the safe's coefficient of kinetic friction on the bank floor?

physics  Henry, Sunday, October 21, 2012 at 9:35pm
Ws = 500kg * 9.8N/kg = 4900 N. = Wt. of safe.
Fv = 4900 N. = Force perpendicular to floor.
Fk = u*Fv = u*4900 = Force of kinetic friction.
Fn = Fap  Fk = m*a
(385+300)  490u = m*0 = 0
685  4900u = 0
4900u = 685
u = 0.140.