# If A and B are two persons at the end of an ideal rope, where A is applying a force of 70N and B is applying force of 60N then what is the force on A? [duplicate]

So according to me in this situation there are two forces acting on A at the moment, one is the reactive force of 70 N by newton's third law and the other is the force of 60 N exerted by B. Now don't you think the tension should be the sum of the two pulling forces experienced by A (i.e. 70+60=130 N)...Please tell me where my thinking process is going wrong.

• @James not exactly Mar 18, 2020 at 18:51
• You've now asked 5 questions on this topic, and aren't happy with the answers. That's fair enough, but I strongly suggest that you do some relevant experiments. Theory is important, but the foundation of physics is empirical evidence from observation & experiment. So get yourself a couple of spring balances, some string, some weights, and some pulleys (or smooth hooks to pass the string over), and do some experiments. Mar 19, 2020 at 12:22
• @PM2Ring Well why do you sound so rude...if you don't wanna answer then it's your wish ...no one is forcing you...but sorry i can't relax unless and until i get my concepts clear..thank you Mar 19, 2020 at 14:32
• Sorry, CuriousMind, I didn't mean to sound rude. I even said that it's fair enough that you aren't happy with the answers you've been given so far. But I think it will be helpful for you to get some literal hands-on experience with this stuff by doing these experiments. It certainly helped me when I was learning this stuff. Mar 19, 2020 at 15:10

Please tell me where my thinking process is going wrong.

Your thinking is going wrong because it violates Newton’s 3rd law. If A is applying a force of 70 N on the rope then by Newton’s 3rd law the rope is applying a force of -70 N on A. That is it. Any other value violates Newton’s 3rd law.

The force exerted by B acts on the rope, not on A.

• But the rope is connecting A and B, if B is pulling A with 60 N then this force must be transfered to A as tension Mar 18, 2020 at 19:13
• That is not necessary, and since it would violate Newton’s laws it doesn’t happen. Instead there is a 10 N net force on the rope so it accelerates.
– Dale
Mar 18, 2020 at 19:18
• Hence what will be the tension of the rope in my case? Mar 18, 2020 at 19:20
• @Dale: See my discussion with OP at his other question. physics.stackexchange.com/questions/536791/… Mar 18, 2020 at 19:33
• okay thank you for your time Mar 18, 2020 at 19:38