How to find tension in a rope when given the force?

In summary: The force of 200N by each athlete is directed along the rope. If the athlete can't move then that must mean that the force the rope exerts on the athlete is equal and opposite the force the athlete exerts on the rope. So the force the athlete exerts on the ground would be 200N.In summary, the tension in the rope in a tug of war between two athletes is 200N, which is also the force exerted by each athlete on the ground if the rope does not move. This can be explained by the principle of action and reaction, where the forces exerted by the athletes on the rope and the ground are equal and opposite.
  • #1
Amelina Yoo
14
0
Moved from a technical forum, so homework template missing
Q: In a tug of war between 2 athletes, each pulls on the rope with a force of 200N.

a) What is the tension in the rope?
b) If the rope does not move, what force is each athlete exerting on the ground?

I wrote for both a) and b) 200N, and I am unable to confirm this because my textbook has no answers. I am also not very confident with this question, and am unable to justify my answers. Can someone please explain how to do this question?
 
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  • #2
Amelina Yoo said:
Q: In a tug of war between 2 athletes, each pulls on the rope with a force of 200N.

a) What is the tension in the rope?
b) If the rope does not move, what force is each athlete exerting on the ground?

I wrote for both a) and b) 200N, and I am unable to confirm this because my textbook has no answers. I am also not very confident with this question, and am unable to justify my answers. Can someone please explain how to do this question?
Your answers are correct, except that in b) I assume the athletes also have some weight.
It sounds like a homework question. If so, it should have been posted in a homework forum.
 
  • #3
Imagine the athlete on one end of the rope. If the rope had more than 200N tension then the athlete would be pulled toward the rope. So the tension in the rope is the same as the force exerted by each athlete, 200N. Suppose the feet of each athlete were affixed to the ground and that their weights are negligible. Let's look again at one athlete. That athlete is are pulling with a force of 200N, the tension in the rope is 200N, they are pushing toward the rope with their feet at 200N.
 
  • #4
OldYat47 said:
Suppose the feet of each athlete were affixed to the ground and that their weights are negligible.
You would also need to assume that the athletes are almost flat to the ground.
 
  • #5
Yes. If the weights are negligible then the forces all have to "line up" in a single line of action.
 

1. How do I calculate the tension in a rope?

To calculate the tension in a rope, you need to know the force applied to the rope and the angle at which the force is applied. You can then use the formula T = F * sin(θ) to find the tension, where T is the tension, F is the force, and θ is the angle.

2. What units are used to measure tension?

Tension is typically measured in units of newtons (N) or pounds (lbs).

3. Can the tension in a rope be greater than the force applied?

Yes, the tension in a rope can be greater than the force applied if the force is applied at an angle. This is because the tension is the component of the force in the direction of the rope, which can be greater than the actual force applied.

4. How does the length of the rope affect the tension?

The length of the rope does not directly affect the tension. However, a longer rope may have more weight and friction, which can affect the tension. Additionally, the angle at which the force is applied can also change the tension.

5. Can I use the same formula to find the tension in a cable or wire?

Yes, the same formula T = F * sin(θ) can be used to find the tension in a cable or wire. However, you need to make sure that the units of force and angle are consistent with the units used in the formula.

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