Some calculations in Newton's Third Law

[ahmed emad]

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.

 

[FactChecker]

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??

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.

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 )

I don't understand your use of the word "lunge" here.

 

[ahmed emad]

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.

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

 

[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 )

 

[abilolado]

If there's no loss of energy due to rebounding or anything else, then yes, you are correct on both.