Question about the stretch of rope

In summary, the conversation discusses a scenario where a rope of length L1 is stretched by two equal forces F1 and F2 from both ends. A metallic block of mass M1 is tied to the center of the rope, causing it to hang down and create a depression of D1 meters. The question asks at what rate A and B should pull the string so that the depression reduces by H1 m/sec, and the differential rate at which both ends of the rope should move to achieve this.
  • #1
aditya ver.2.0
67
4
A rope of length L1 is stretched from both ends by A and B ( both are exerting equal amount of force F1 and F2, where F1=F2)to keep it rigid. Just then C ties a metallic block of mass M1 at the center of the rope.Due to the weight of the block, the rope hangs down and creates a depression of D1 meters.

Q.1 At what rate (in Newton) should A and B pull the string so that the depression starts to reduce by H1 m/sec, in the presence of the metallic block?

Q.2 At what rate (or differential rate) should both the ends of the rope move, so that the depression reduces by H1 m/sec?
 

Attachments

  • Untitled.jpg
    Untitled.jpg
    8.6 KB · Views: 438
Physics news on Phys.org
  • #2
Hi. This looks like a Homework / Coursework question and it should probably be in that forum.
As we don't just answer such questions 'for free' (PF is far too mean to spoon feed people!), we need to see what you, yourself, have done towards answering the question.
For instance, what are the forces acting on the Mass M1 and what would be the tension in the rope?
 
  • #3
Sorry Sir, I am beginner in this section. Urgently want to learn how to solve such question. Please...
 
  • #4
Sophie is correct. This question belongs in the homework forums. Please repost it there and use the template provided when you click on New Post. Note that PF is not here to teach you how to solve such questions from scratch. If you have no idea where to begin then you should seek help from your teacher or someone in your class.
 
  • #5


I would approach this question by first considering the forces acting on the rope. Since the rope is being stretched from both ends by equal forces, it is in a state of equilibrium and not moving. When the metallic block is added, its weight creates a downward force on the rope, causing it to hang down and create a depression.

To answer the first question, we need to determine the force required to counteract the downward force of the block and reduce the depression by H1 meters per second. This can be done by using the equation F=ma, where F is the force, m is the mass of the block, and a is the acceleration. Since we want the depression to reduce by H1 meters per second, the acceleration of the block must be equal to H1. Therefore, the force required to achieve this acceleration would be F=M1*H1. Since A and B are exerting equal forces, each of them would need to pull with a force of F/2, or (M1*H1)/2, in order to achieve the desired reduction in depression.

For the second question, we need to determine the rate at which both ends of the rope should move in order to reduce the depression by H1 meters per second. This can be done by using the equation v=√(2gh), where v is the velocity, g is the acceleration due to gravity, and h is the height of the depression. In this case, the height of the depression is D1, so the velocity required to reduce it by H1 meters per second would be √(2g(D1-H1)). Since both ends of the rope are moving, each end would need to move at a rate of v/2, or √(2g(D1-H1))/2, in order to achieve the desired reduction in depression.

In conclusion, in order to reduce the depression by H1 meters per second, A and B would need to pull the rope with a force of (M1*H1)/2 and both ends of the rope would need to move at a rate of √(2g(D1-H1))/2. It is important to note that these calculations assume ideal conditions and may vary in a real-world scenario.
 

1. How do you measure the length of a stretch of rope?

The length of a stretch of rope can be measured by using a measuring tape or ruler to measure from one end to the other in a straight line. It's important to make sure the rope is taut and not twisted when measuring.

2. What factors can affect the stretch of a rope?

The material and thickness of the rope, as well as the amount of weight or tension applied, can affect the stretch of a rope. Other factors such as temperature and exposure to moisture can also impact the stretch of a rope.

3. How can you increase the stretch of a rope?

The stretch of a rope can be increased by adding additional weight or tension to it. This can be done by adding more weight to one end of the rope or by using a pulley system to increase tension.

4. Is there a limit to how much a rope can stretch?

Yes, there is a limit to how much a rope can stretch. This limit is often referred to as the breaking point or maximum elongation. It is important to not exceed this limit as it can lead to the rope breaking or becoming damaged.

5. Can the stretch of a rope be predicted?

The stretch of a rope can be predicted to a certain extent based on its material, thickness, and the amount of weight or tension applied. However, there may be slight variations due to external factors such as temperature and moisture.

Similar threads

  • Introductory Physics Homework Help
Replies
33
Views
6K
  • Advanced Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
6
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
2K
  • Introductory Physics Homework Help
Replies
15
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
3K
  • Introductory Physics Homework Help
Replies
6
Views
3K
  • Introductory Physics Homework Help
Replies
2
Views
1K
Replies
16
Views
5K
  • Introductory Physics Homework Help
Replies
5
Views
3K
Back
Top