 # Newton's third law of motion

## (6)Newton's third law of motion

• Statement of newton's third law of motion is " To every action there is always an equal and opposite reaction".
• Thus,whenever a body exerts force on another then another object exert an equal force on previous body but in opposite direction
• Force example motion of rocket depends on the third law of motion i.e, action and reaction .Rocket exerts action force on gas jet in backward direction
• Force of action and reaction acts on different objects i.e,
Force object 1 exerts on object 2= Force object 2 exerts on object 1
i.e,
F12=-F21
Action=-(Reaction)
• According to Newtonian mechanics force is always a mutual interaction between the bodies and force always occurs in pairs
• Equal and opposite mutual forces between two bodies is the basic idea between Newton's third law of motion
• While considering a system of particles ,internal force always cancel away in pairs i.e consider two particles in a body if F12 and
F21 are internal forces between particle system 1 and 2 then they add up to give a null internal force.Same way internal forces for the particles