1. The problem statement, all variables and given/known data A 2kg block sits on a 4kg block that is on a frictioness table. The coefficients of friction between the blocks are U(s)= .3, U(k)=.2 a. What is the max horizontal force that can be applied to the 4 kg block if the 2 g block is not to slip? 2. Relevant equations Fr = μN 3. The attempt at a solution N= (2kg)(g)= 19.62 N Fr = μN= (19.62)(.3)=5.886 I chose to use the coefficient for static friction because kinetic frition is for sliding objects, and we do not want the block of 2 kg to be sliding. With this information I came to the conclusion that the max force that could be applied to the 4kg block without the 2 kg block slipping would be 5.886N because that is the frictional force between the two objects. The answer in the back of my book is 18N, and I can't figure out how to arrive at this answer.