Question

A 70 kg man pushes a man of 50 kg. by what force the man pushed pther

Answer 1

A 70-kg man pushes a 50-kg man by a force of 70 N. Actually, the 50-kg man didn't push the 70kg man. Did you mean what would the reactive force be against the 70-kg man?

According to Newton's Third Law of motion, it would be exactly equal to the force applied to the 50-kg man by the 70-kg man.

If they were both motionless and weightless when Mr. 70 shoves Mr. 50, they will both feel the 50 N force, Mr. 50 as a result of Mr. 70’s push, and Mr. 70 will feel it as Mr. 50’s resistance to his push.

Since Mr. 75 weighs 50% more than Mr. 50,that means that Mr. 50 will move away from their point of contact 50% faster. If you want their actual speed, you can do the math.