A book sits on a horizontal top of a car as the car accelerates horizontally from rest.If the coefficient static of friction between the book and the car top is 0.450,what is the maximum acceleration the car can have if the book is not to slip?

Question

I remember when as a Electrical Engineering student at the University of Texas, one morning I looked in my mirror and saw my books and papers behind in the street. I forgot to put them in when unlocking the car. So goes all night studying.

The weight of the books is mg, so the maximum force of friction is mg*mu.
This is equal to m*acceleration.
set them equal, and solve for acceleration. Notice mass m divides out.

Answer 1

4.41

Answer 2

Useless