Question

A block is placed on the horizontal surface. There are two forces acting on the block. One,the down ward pull of gravity and other a normal force acting on it. Are these forces equal and opposite? Do they form action -reaction pair? Discuss with your friends

Answer 1

No. The gravitational pull by earth on the object and the gravitational pull by the object on the earth form the third law pair. The normal force on the object by the earth and normal force by object on the earth forms third law pair. You can easily see this by looking at their FBD. Magnitude wise, they are equal, but do not form action reaction pair.