posted by Dorothy .
I have 3 different questions.
1) Calculate the coefficient of kinetic friction if it takes a force of 64 Newtons to keep a 54 kilogram box of books sliding across any icy surface at a uniform speed.
2) A car weighing 14,000 Newtons rests on a 20.0 degree incline. Calculate the component of its weight which acts down the incline.
3) A 15.0 kilogram crate rests on the classroom floor. The coefficient of static friction is .38 and the coefficient of kinetic friction is .26. What force is required to start the crate sliding across the floor?