# What is Rope: Definition and 834 Discussions

A rope is a group of yarns, plies, fibers or strands that are twisted or braided together into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting. Rope is thicker and stronger than similarly constructed cord, string, and twine.

View More On Wikipedia.org
1. ### B Help answer student question about infinity?

Hi, my background isn't mathematics but I was wondering how this kind of problem might be approached. They have asked if there was a knot somewhere in an infinitely long rope, would the knot ever be reached if you iterated through the length hand over hand? How could I start to tackle this...
2. ### Find the tension in the rope PQ

My interest is on part (a), the steps are clear. I thought the final solution ought to be ##T- 500 =50 ×0.2## ##T=500+10 = 510N## Unless I am missing something here, same query on part (b).
3. ### B Slack vs tight rope at the start of a pendulum

Pretty much what the title says. Everything that I can find online addresses the pendulum problem with the assumption that the rope is under tension to start. What if the rope is slack to start? Will there be an increase in force applied to the pivot point, say if a mass is dropped off a...
4. ### Rope Swing, starting in tension vs slack

I'm the technical director for a theatre group and am looking at the best way to get an actor to use a rope to swing on stage. As we rent the theatre we use I need to run everything by their staff, who doesn't have a solid grasp of mechanics and physics. I proposed that we lower a pipe from...
5. ### If a rope is in free fall, does tension force act on it or not?

This is the question. To this point everything is clear. I have problem with following part: The authors claim that each part of the remaining rope is under constant acceleration. So it is in free fall and only gravitional force acts on it. If we release a rope like above, before it hits the...
6. ### A sphere held steady on a slope by a rope

The sum of the forces should be 0. Sin A'C'B' = px/b px = mg . sin alpha P should be px = - m.g. sin alpha and py = m.g.cos alpha Finally i fund as result F = -0.8 and R = -1.23 but for the second question i didn't fund the radius of the circle.
7. ### A rope, a pole, and some tension

A rope wraps an angle θ around a pole. You grab one end and pull with a tension T0. The other end is attached to a large object, say, a boat. If the coefficient of static friction between the rope and the pole is µ, what is the largest force the rope can exert on the boat, if the rope is not to...
8. ### Tension in Rope Wrapped Around a Rod

On question B, I've attempted a solution that I have posted. However, I don't think it's correct. Am I allowed to treat this rope that wraps around the rod as a "negative" force and simply attach it to the other side of the equation such that ## m_1g=m_2g+\mu_sN##?
9. ### B Finding the spring constant of a rope

The 7/8" Kinetic Recovery Rope like this yankum rope is the most common size used for Jeeps, Broncos, and other SUVs. I apologize for English units but that's how ropes are sold and marketed. I've talked to the biggest rope suppliers and they have no idea how to compute the rope's spring...
10. ### B Rope wrapped around a rod - belt friction

Ideally, it should look circa like this: But in reality, it looks often like this: Is the formula valid also in this case?
11. ### Backyard Tow Rope Troubleshooting: Motor Binding Issues

Hello - We are building a backyard tow rope for my course. All of the electrical components are working as designed; however, the pulley can't consitently grip the rope when only placed around the rim. When looped around 1.5 times the rope continually shifts underneath itself causing the motor...
12. ### Variable mass, uniform body, force -- pulling a massive rope

So i got some equations but i think i am missing something, my main doubt is what is the relation between dx / dt and v(o) [ here] . Workings in attachment
13. ### Work, Power and Energy — Lifting a coiled rope up off a surface

The solution said that Average power= net change in energy/time, but why is that true? If you have a different way of solving it, it would be helpful too
14. ### How does this system work? (Four pulleys and a rope lifting a mass)

I used the regular way of solving problems with pulleys. I tried to find the tension forces, which must be the same in the rope, but I get it wrong
15. ### Wind drag problem with a ball hanging on a rope

I drew a FBD but I feel like it's wrong because there are too many missing values. I tried this: Fy = 0 Tcosθ - Fg = 0 Tcosθ = mg T = (1.2)(9.8) / cos(25) T = 12.98 N Fx = ma Fwind - Tsinθ - Fdrag = ma Fwind - (12.98)(sin25) - Fdrag = ma I don't know how to find these missing values. I feel...
16. ### Pulling a crate across the floor with a rope at an angle

I drew out a motion diagram and used 115N sin(26.7 degrees) = 51.7 N but It turns out to be wrong.
17. ### Forces on a rope when catching a free falling weight

If I am not wrong, F = 2*10*9.81*4/0.2 = 3924N (0.2m considering 5% stretch in 4m long rope)
18. ### Mystery of a Tensioned Rope Split in Two Places

I'm attempting to repair my Ergotron Workfit station. After taking apart, I discovered the problem. A single nylon rope split, releasing the spring's tension. Because it is past the warranty, the manufacturer is recommending I toss the whole assembly and buy a new \$650 one. Doesn't seem the...
19. ### Calculating Max Tension, Final Angle for Swinging on Rope Over Lake

Please tell me if I need to post my solution for this.., but I just have a question more or less 'conceptual' question about (c). so I know that from Newton's 2nd law for centripetal acceleration --> ##F_{rope} - mgcos(\theta) = ma_n## where ##a_n = \frac {v^2}{R}## such that where the normal...
20. ### What causes knots and stress when untwisting ropes?

[Mentor Note -- thread moved from the schoolwork forums to GD as it seems like a more general question] Homework Statement:: Topoisomerases help in relieving strain in the DNA ahead of the replication fork caused by the untwisting of the double helix (Topoisomerases are enzymes that...
21. ### I Shock Load on Rope: Weight Limit Analysis

Hello, I’m not sure if the proper term is shock load. If a person is using a device and rope to lower themselves from a high point and they’re descending fast and then suddenly stop does that create a shock load? The device attaches to the rope and when a person squeezes the device it allows...
22. ### Block of mass M attached to rope of mass m

We have the string's mass constraint m(x) = m(x/L). The block is accelerated right by force T(x=0) = Ma, where a = F / m + M. But at the point where the force is applied (i.e. x = L), I believe we have m(L/L)a = ma = F - T(L). But this would imply T(L) = F - ma = F - m(F / m + M) = F(M / m + M)...
23. ### Direction of motion of points on a rope as a wave travels

The second diagram is my attempt at the solution, in which the dotted part is the pulse in the rope a very small interval of time after ##t=0##. Point A should be at rest since we know wave is moving towards right and point A on the rope becomes a part of initial horizontal part of the string a...
24. ### B What is tension and how does it affect a rope?

I have gathered everything from post “Monkey climbing up the rope” about tension. Tension is basically a force that the rope applies back when it is under stress. It is an inward force. Tension T's direction at end points of rope where its attached to the body and ceiling is inwards. Tension is...
25. ### What is the tension in a rope when a monkey accelerates up?

I think the tension in the rope will be equal to its weight , mg. I want to ask what if the monkey accelerates up with acceleration a, then what will be the tension in the rope?
26. ### Two masses connected by a rope on a pulley on a ramp

I have no clue how to do the problem. I created a free body diagram for each block. I assume that it is simpler than I am making it out to be.
27. ### Tension on both sides of the rope is supposed to be the same?

The diagram represents one half of the system. ##W## is the weight of the man. ##T_1 cos \theta = T_2## --> The horizontal component of ##T_1 = T_2## right ? ##T_1 cos \theta = T_1 \frac {d}{\sqrt {4h^2 + d^2}} = T_2## ##T_1 sin \theta = \frac {W}{2}##...
28. ### Morin's mechanics problem 2.3 (motionless chain)

In his solution, Morin solves the problem as the hint suggests: cutting the chain into small pieces, taking the component of the external forces along the curve (which is just the component of gravity here) and summing up an in integral, obtaining 0. He then claims that because the "total...
29. ### Tetherball rope wrapping around a pole

My work so far is pretty basic, but I'm not too sure how to continue off from here. I haven't included the 2 dimensional aspect of it either, but I would presume that the rate of decrease in length is more sped up in that case? Would appreciate any help :(
30. ### I Calculating Power Requirements for a Ski Tow Rope with Friction | 18.9% Incline

Hi Everyone - I found a previous post here that has helped me size an engine for a ski tow rope but wanted to take that a step further an add friction into the equation. If I followed that problem corrected, the tow rope requires 821W calculated as follows: power = work/time...
31. ### Vertical spring connected between two bodies with a rope above them

Question: A string spring is connected between two bodys with a rope above them. M1 = 25Kg M2 = 50KG Distance between them is 100m. I answered a bit and got to the point where the distance between the two masses are 110m ( the mass below got 10m lower and is on balance, I mean, acceleration = 0...
32. ### Two Mass Three Rope Tension Problem

What I did first is to find the tension T1 and T2; T1=(mg)/[sin(55)] T1=(40N)/[sin(55)] T1=48.83N T2=T1cos(55) T2=(48.83N)[cos(55)] T2=28.01N Now I do not know how to proceed. Can someone help me?
33. ### Finding acceleration of block with block on top, connected by rope

I have already concluded that the way to solve this problem is through (20 N - (3 kg * 9.8 m/s^2 * 0.16) - (2*(1 kg * 9.8 m/s^2 * 0.16))) / 3 kg I have several questions: Why do we multiply the second set of parentheses by 2? Why do we count the friction between the 1 kg box and the 2 kg box...
34. ### Newton's law problem: Helicopter lifting a box with a rope

Forces: Box--> W(weight) and T(tension) Rope-->T1(reaction of T) and T2(because of the helicopter) So first i calculated Weight: W=mg=400*10=4000N In order to find the acceleration i should use Newton's 2nd law so: (Box) : T - W = ma T - 4000=400a The problem is with the rope...
35. ### I Drawbridge falling before caught by rope/cable - Max force

Hi, I'm currently looking into the forces exerted on a cable if the cable was to go from slack to taut due to a falling object that is pivoted about a lower hinge - such as a drawbridge but instead of slowly lowering, there is slack in the cable causing the bridge to freely rotate about the...
36. ### Two Pulleys, Two Strings and Two Blocks

Someone pls solve this. I've done it but I'm not sure if it's correct. Thanks!

38. ### Find the unknown mass on a inclined rope pulley system.

First I calculated the forces that were working against mass B. m(A)g sin 30 + μm(A)g cos 30 = 12.86 N The force working with mass B is m(B)g = 9.8m(B) I thought I could solve for B using F=ma where 12.86 N = (2kg+m(B))*(0.58), but of course, 12.86 N is just the force required to make the...
39. ### Please check my solutions -- Mass being pulled with an angled rope

A block of mass M = 4 kg is pulled by a force F = 100 N forming an angle of 60 degrees with themhorizontal plane with friction coefficient 0.3. Determine the work of force F, friction force and normal force.
40. ### What is the tension of the rope?

I have attached two different attempts to solve this problem. They both look correct to me but they give two different answers! Which one is correct, which one is wrong and why?
41. ### Engineering Crate lowered by two ropes and deceleration at each point of contact with rope

For this question, I don’t understand the steps for the relative motion part. When I try it I get angular acceleration to be zero which is obviously wrong. The solution doesn’t consider the Y distance between G and A but I don’t understand why. In the relative motion equation it’s suppose to be...
42. ### Tension in rope for non-uniform circular motion with air resistance

I'm trying to solve this problem using an rtz coordinate system, and Newtons second law. I know that mar = (m(v)2)/r. I'm failing to understand how mg and the drag force affects the solution and how I would set it up. I know if it was at the bottom of the circle that mg would be added to the...
43. ### Pulling a sled across snow with a rope at an angle

Hello. Can someone tell me what area of phisics should I study to better understand this exercise and also what should I do to solve this exercise please? A man pulls a small sledge with a force F ⃗ of intensity equal to 50.0 N and that makes an angle with the horizontal θ = 30º (see figure)...
44. ### Angle on ramp with cart and weights on rope at end

I believe the nx, Ty, and (fs)y are all 0. I could solve for theta if I could figure out (fs)x or ny. edit: Track is frictionless, so delete (fs) forces.
45. ### Speed of a hanging rope sliding on a nail (using energy conservation)

I solved this problem easily using Newton's second law, but I had problems trying to use mechanical energy conservation to solve it. How I solved using Newton's second law: ##\text{(part of the rope that is on the left)}\, m_1=x\rho g,\, \text{(part of the rope that is on the right)}\...
46. ### I Seesaw problem with a man connected to a fan by a rope

Men is at seesaw , connected with rope to beam which is conected to seesaw with joint,when fan is off ,seesaw is stay at brawn box. When you turn ON fan,man and beam are in balance,can seesaw flip to right side? (If beam is conect with fixed conect to seesaw then for sure it will flip to right...
47. ### Friction of a rope around a cylinder

Hi, We have a cylinder held by a rope . The rope holds it around its lower half. If the center of mass of the cylinder is not in the middle, but towards a side, a distance "a". How does this offset affect to the friction on the rope? or How big does "a" have to be so the cylinder starts...
48. ### Friction between pulley and rope

I have a question about friction between pulley and rope? Does anyone know how to calculate friction between pulley and rope I enclosed an example picture Thank you!
49. ### Tension in a rope holding a mass under a helicopter rising at constant speed

Helicopter lift weight of 500kg ,weight is connect with load cell to meassure tension. Neglect aerodynamic drag.. If helicopter accelarate up ,tension is rope is greater than 500kg. If helicpter accelarate down ,tension is rope is less than 500kg. If helicopter fly up with constant speed...
50. ### Point mechanics -- Tension in a rope from a hanging mass

Hi, I'm being asked to determine the tension of a rope only knowing that g = 9.8 m.s-2. I understand that in order to calculate tension, I would need to multiply mass with acceleration. But i don't understand how i would in this case. This is the question for reference. Thanks for your help...