How Do Newton's Laws Explain the Motion of Two Men Pushing Each Other?

[pkc111]

Homework Statement

An 80 kg man (A) pushes another 80kg man (B) with a force of 500N, describes what occurs.

Homework Equations

Newtons 2nd and 3rd Law ?

The Attempt at a Solution

I suspect the answer is both men fly apart with an acceleration of (500/80) m/s2 ? But in real life I would imagine man A would stay put ?

 

[tiny-tim]

Hi pkc111!

An 80 kg man (A) pushes another 80kg man (B) with a force of 500N, describes what occurs.

Answer 1:

Are they on ice? or in space?

Is each man standing with feet side-by-side, or in-line?

Are their weights being supported on their heels or their toes?

Is the force applied to B at this centre of mass?

If this is a physics question, there's nowhere near enough information.

If it's a sociology question, I'd say they're equally matched, so there'll be a fight! ​

Answer 2:

The force is given in Newtons, so it's not an impulse (which would be in Newton.seconds).

So the question must mean that the force is being applied continuously, which means that A and B must be staying together, with acceleration of … ?

 

[nlightner]

Your suspicion is correct. According to Newton's third law of motion, for every action, there is an equal and opposite reaction. In this scenario, the force of 500N applied by man A on man B will result in man B exerting a force of 500N back on man A. This will cause both men to experience an equal and opposite acceleration, causing them to move away from each other. However, in real life, factors such as friction and the stability of their footing may affect the outcome and man A may not necessarily stay put.