# Tension Force (Quiz #4 q.19)

1. Aug 30, 2014

### gcombina

19. In a tug-of-war, each man on a 5-man team pulls with an average force of 500 N. What is the tension in the center of the rope?
(a) zero newtons (c) 500 N (e) 5000 N
(b) 100 N (d) 2500 N

My answer was 2500 N as that is teh force pulling the rope, why the answer is 5000??? are we talking about a 5-man team on EACH side????/

Thanks!

2. Aug 31, 2014

### nrqed

Yes, there is a team on each side (otherwise there would be no tension, they would all fall :-) )

3. Aug 31, 2014

### Staff: Mentor

Yes, two teams. Not much fun without an opposing team!

4. Aug 31, 2014

### SammyS

Staff Emeritus
Assuming that there is negligible acceleration, and that the center of the rope is somewhere between the two teams, then Newton's Third Law says you're correct, the center of the rope is exerting a force of 2500 N on the team in question. (Of course, the opposing team would be exerting a force opposite that of the 5 man team with a magnitude very close to 2500 N. The center of the rope also exerts a force of 2500 N on that opposing team as well, but those don't sum to be 5000 total.) This simply how Tension in a rope is expressed.

5. Aug 31, 2014

### ehild

There are people pulling the rope at both sides, but your answer is correct. The tension is the same all along the rope. Pulling the rope with the same force (2500 N) at both ends, the rope and people are in rest as the net force on the rope is zero. The five people at the right end pull the rope with 2500 N to the right and the rope pulls the people back with its tension, which should be 2500 N. The tension is the same everywhere in the rope: it pulls the people at the other end with the same force, to the right, so those people have to pull with 2500 N force to the left. No way to get 5000 N for the tension.

6. Aug 31, 2014

### Staff: Mentor

Not in any of the team tug-o-wars I've seen!

7. Aug 31, 2014

### SammyS

Staff Emeritus
It is the same all along the portion that is between the two teams.