**Question:**

Understand the third equation of motion

The question is third equation of motion not third law of motion.

M1U1+M2U2=M1V1+__M2U2__

To every action there is equal and opposite reaction

Every action has an equal an opp reaction and these force act on two different __body__

Every action their is an equal n opposite reaction

For every action there is equal and opposite reaction force.

Demo

__backward__

To every action their is an equal reaction

The third equation of motion gives the equation :-

V²=u²+2as