A book of mass m is at rest on the table.
(1) What are the forces acting on the book?
(2) What are the forces exerted by the book?
(3) Draw the free body diagram for the book

Explanation

(1) There are two forces acting on the book.
(i) Gravitational force (mg) acting downwards on the book.
(ii) Normal contact force (N) exerted by the surface of the table on the book. It acts upwards as shown in the figure.
(2) According to Newton.s third law, there are two reaction forces exerted by the book.
(i) The book exerts an equal and opposite force (mg) on the Earth which acts upwards.
(ii) The book exerts a force which is equal and opposite to normal force on the surface of the table (N) acting downwards.
(3) The free body diagram of the book is shown in the figure