A chemistry book whose weight is 13N is placed on top of the history book in figure, making it a stack of three, not two. Identify each force on each book with an approprate double-subscript notation and determine the magnitude and direction of each of these forces. How many times do you apply Newton’s third law and how many times do you apply Newton’s second law in finding these forces?

A chemistry book whose weight is 13N is placed on top of the history book in figure, making it a stack of three, not two. Identify each force on each book with an approprate double-subscript notation and determine the magnitude and direction of each of these forces. How many times do you apply Newton’s third law and how many times do you apply Newton’s second law in finding these forces?