Is My Assumption About Rope Tension Correct?

Click For Summary
SUMMARY

The discussion centers on the tension in a rope system when one rope is cut, specifically analyzing the scenario where an object hangs vertically with a load of 5N. Participants clarify that the tension in the remaining rope immediately after cutting the other rope is not simply 5N, as the system experiences acceleration. The correct approach involves calculating the weight of the mass using force vectors and understanding that the tension will change due to the dynamics of the system. Ultimately, the tension in the remaining rope is determined to be 10N after considering the weight of the object and the angle of the rope.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Knowledge of force vectors and their components
  • Ability to draw and analyze free body diagrams
  • Familiarity with trigonometric functions in physics
NEXT STEPS
  • Study the principles of Newton's second law and its application to dynamic systems
  • Learn how to construct and interpret free body diagrams for various scenarios
  • Explore the concept of tension in ropes and its dependence on angles and weights
  • Investigate the effects of acceleration on tension in multi-rope systems
USEFUL FOR

Students studying physics, particularly those focusing on mechanics, as well as educators seeking to clarify concepts related to tension and force analysis in rope systems.

  • #31
haruspex said:
Yes, it's wrong. (That would be the right answer if the angle were 45 degrees.)
You have established that the weight is 10sin(60) N. Draw a free body diagram, exactly like the original diagram, but with only one rope.
So the rope is still at 60 degrees to the horizontal.
Let the tension in the rope be T. You know the weight, and hence the mass. The tension and the weight are the only forces acting, agreed?
Which way will the mass accelerate?
What can you therefore say about the forces orthogonal to that direction?

thank you very much for your guide..i will try your idea. i hope you have time to check it
 
Physics news on Phys.org
  • #32
stuc said:
thank you very much for your guide..i will try your idea. i hope you have time to check it
haruspex said:
Yes, it's wrong. (That would be the right answer if the angle were 45 degrees.)
You have established that the weight is 10sin(60) N. Draw a free body diagram, exactly like the original diagram, but with only one rope.
So the rope is still at 60 degrees to the horizontal.
Let the tension in the rope be T. You know the weight, and hence the mass. The tension and the weight are the only forces acting, agreed?
Which way will the mass accelerate?
What can you therefore say about the forces orthogonal to that direction?
4 ans.jpg


dear haruspex ... is it like this?
 
  • #33
stuc said:
View attachment 92448

dear haruspex ... is it like this?
The free body diagram is right, but you need to think about which way the acceleration must be. In your force analysis, you have summed the vertical components and assumed the total to be zero. In other words, you have supposed the acceleration to be horizontal. Clearly it will not be. Which way will it be?
 

Similar threads

How do varying forces on a massless rope affect tension?
  • · Replies 2 ·
Replies
2
Views
2K
Is it friction or tension acting on the person hanging on a rope?
  • · Replies 4 ·
Replies
4
Views
1K
Calculating Max Tension, Final Angle for Swinging on Rope Over Lake
  • · Replies 43 ·
2
Replies
43
Views
5K
Find tension of a rope and kinetic force
  • · Replies 13 ·
Replies
13
Views
3K
Solve Tension in Rope: 110 Kg Anvil & 9.81m/s^2 Force
  • · Replies 13 ·
Replies
13
Views
2K
Tension in Rope Wrapped Around a Rod
  • · Replies 9 ·
Replies
9
Views
2K
Why Does Tension Vary Along the Rope in a Hanging Superhero Scenario?
  • · Replies 5 ·
Replies
5
Views
8K
Tension on a Massive Rope: How to Calculate Tension at Different Points
  • · Replies 11 ·
Replies
11
Views
3K
Problem with pulleys - two fixed and one movable
  • · Replies 22 ·
Replies
22
Views
1K
Tension in a rope hanging between two trees
  • · Replies 7 ·
Replies
7
Views
9K