Problem with Dynamics H.E.L.P please

[Azeri]

"What is the tension of the rope if 2 boys pull it in opposite directions with equal forces of 40N?"

I guess it is 40N but not sure why.

THX for help.

 

[arildno]

Hint:
Every piece of the rope is also in equilibrium, (not just the WHOLE rope)!
So, look at the half-rope with one boy at one end.
The half-rope is in equilibrium, hence, the rest of the rope must act upon it with a tension equal to...?

 

[wais]

Yes, the tension of the rope would be 40N in this scenario. This is because when two equal forces are applied in opposite directions, the net force on the rope is 0N. According to Newton's First Law of Motion, an object at rest will stay at rest or an object in motion will continue to move at a constant velocity unless acted upon by a net external force. Since the rope is not accelerating, the net force on it must be 0N. Therefore, the tension in the rope must be equal to the forces applied, which in this case is 40N on each side. I hope this helps!