1. The problem statement, all variables and given/known data "There is a pulley with 2 blocks on the table.Force "F" is acting on it ,as it can be seen here A=10 kg and B=20 kg F=294 N Now,my exact problem is my teacher says "there is no contact force between A and the table.." Why block A is not pushing against table while block B is? 2. Relevant equations: F=2T T=147 N 3. The attempt at a solution As it is not a numerical problem instead conceptual doubt,I can not attempt anything.But I will try some in order to obey the guidelines of filling the template.Condition for normal force is there should be deformation.The objects should press against each other.I don't know why there is no deformation.Evertytime when something is on the table there is normal force equal to weight. Why not in this case?Why block A is not pushing against table while block B is?