(a) Firing a bullet from a gun — When a man fires a bullet from a gun, a force F is exerted on the bullet (action) and the gun experiences an equal recoil R (reaction).
(b) Hammering a nail — When we hammer a nail, the hammer exerts a force F (action) on the nail and the nail in turn also exerts an equal and opposite force R (reaction) on the hammer.
(c) A book lying on a table — When a book is placed on a table top, the book exerts a force equal to it’s weight (action) on the table in downward direction and the table balances it by an equal force called the (reaction) acting upwards on the book.
(d) A moving rocket — The rocket exerts a force F (action) on gases (produced by burning of fuel) to expel them through a nozzle backwards. The outgoing gases exert an equal and opposite force R (reaction) on the rocket due to which it moves in the forward direction.
(e) A person walking on the floor — When a man applies a force F (action) backward by his foot on the ground against the force of friction, the ground exerts an equal and opposite force R (reaction) forward on his foot.
(f) A moving train colliding with a stationary train — The moving train exerts a force F (action) on the stationary train and the stationary train in turn exerts a force R (reaction) on the moving train.
