Why the total tension is not zero?

[Aruna Kiran]

If two ends of a rope in equilibrium are pulled with forces equal in magnitude and opposite direction,why the total tension in the rod is not zero?

Homework Equations

The Attempt at a Solution

 

[Doc Al]

Don't confuse the net force on a section of rope with the tension in the rope.

 

[SteamKing]

What rod? I thought you were pulling on a rope.

 

[Aruna Kiran]

Could you please elaborate your answer? I still can't get it.

 

[Doc Al]

Could you please elaborate your answer? I still can't get it.

If you pull each end of piece of rope with a force of 50 N (for example) you will create 50 N of tension in the rope. Think of the tension as the property of a stretched rope that allows it to exert a force at each end.

While the tension is 50 N, since you're pulling each end with equal and opposite force the net force on the rope is zero.

 

[CWatters]

The two forces are acting on different points. Imagine you cut the rope into three bits and knot it back together so that you have one rope again made from three bits A,B,C

If you exert a force on part A (and C) then part A will exert an equal force on part B. Then according to Newton, part B will impart an equal and opposite force on part A. Because of symetry the same is happening at the other end. So part B is under tension. Part B can be any size, upto and including the entire rope.

 

[Aruna Kiran]

Oh. I got it now. Thank you all.