# I Some calculations in Newton's Third Law

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1. Jul 1, 2017

Hello,
1- IF we have an object has 200 kg and we also have a machine has 5 kg and pushes that object with force of 600 n , in newton third law it must be another force =-600n then : the acceleration of the object must be 3 m\s^2 and the acceleration of the machine is 120 m\s^2 , Am I wrong??

2- if I am in vacuum and I dropped an apple and the distance between my hand and the floor =5 m , is the apple must lunge with 5 m also?? (I said vacuum because I think that the thing causes apple not lunge at the same distance is the air resistance )

And thank you.

2. Jul 1, 2017

### FactChecker

You are essentially correct, but be careful about the signs of the accelerations. They would be in opposite directions, so they would have opposite signs in any coordinate system.
I don't understand your use of the word "lunge" here.

3. Jul 1, 2017

sorry I am not talk English extremely ,I am from egypt
I meant Rebound
and thank you

4. Jul 1, 2017

### FactChecker

Ok. The rebound height would depend on the elasticity of the object. Something with perfect elasticity would bounce back to 5 m (ignoring the reaction motion of the Earth). A real apple would primarily squash instead of bouncing. The coefficient of restitution tells how much the object will bounce. (see https://en.wikipedia.org/wiki/Coefficient_of_restitution )

5. Jul 2, 2017