Pulley Definition and 1000 Threads

  1. S

    What is the efficiency of a pulley and how do we calculate it?

    Homework Statement I'm on my last question for my coursework and this is it. I have managed to find out how to calculate the efficiency of a pulley but not "what is the efficiency of a pulley" Could someone please help me. Homework Equations Efficiency = (Mechanical Advantage /...
  2. G

    Pulley Efficiency Problem (How much rope must be pulled)?

    Homework Statement A pulley system has an efficiency of 71.5 percent. How much of the rope must be pulled in if a force of 641 N is needed to lift a 160 kg desk 2.51 meters? Homework Equations IMA = De/Dr MA = Fr/Fe Efficiency (%) = Wo/Wi Efficiency (%) = MA/IMA I have absolutely...
  3. H

    Two trucks are around the pulley

    (see image) How do I go about this? since a1 is larger, and the two trucks are around the pulley, then a2 is opposing (to some extent) so i thought the answer would be a1-a2? but I checked the answer and it's a1+a2/2 please help thank you :)
  4. L

    Which Equation Determines Angular Displacement for a Rotating Pulley Wheel?

    Homework Statement A solid pulley wheel is rotated at a constant velocity for 10 sec's. Find the angular displacement? Wo (inital angular velocity) = 6Rad/s W (angular Velocity) = 0 Rads/s \alpha = 0 (angular acceleration) Rads/s-2 θ = ? (angular displacement) Rads/s t = 10 sec...
  5. L

    Calculating Tension and Friction in a Pulley System

    Pulley Tension friction help?? Homework Statement http://www.flickr.com/photos/72384417@N06/6533043261/ by LiFK1, on Flickr Mass1 = 0.750 kg Mass2 = 0.52 kg Fk=2.1 N g= 9.8 N Homework Equations F=ma Mass1(gravity)= (Mass1+mass2)Acceleration T + m2g - fk = (m1 + m2)a...
  6. L

    How Do You Calculate Tension in a Three-Mass Pulley System?

    Homework Statement In the figure below, M1=1.00 kg, M2=2.00 kg and M3=4.00 kg. Theta is 30.0°. The pulley and all surfaces are frictionless. Find the tension in the two strings and the direction (entire system to the left/counterclockwise or entire system to the right/clockwise) and...
  7. I

    Three Masses - pulley, rotational and translational forces

    An green hoop with mass mh = 2.4 kg and radius Rh = 0.18 m hangs from a string that goes over a blue solid disk pulley with mass md = 2.4 kg and radius Rd = 0.09 m. The other end of the string is attached to a massless axel through the center of an orange sphere on a flat horizontal surface that...
  8. B

    Two Masses Hanging on a Massive Pulley

    Homework Statement A pulley with mass Mp and a radius Rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot. Mass M2 is larger than mass m1. The quantities Tn and g are magnitudes. (image attached) Select T-True, F-False, G-Greater than...
  9. B

    Upward Acceleration of a Hanging Mass Connected to Another By a Pulley

    Homework Statement A 26.3 kg block (m1) is on a horizontal surface, connected to a 7.10 kg block (m2) by a massless string as shown in the figure below. The frictionless pulley has a radius R = 0.060 m and a moment of inertia I=0.090 kgm2. A force F = 220.1 N acts on m1 at an angle theta =...
  10. L

    How Do You Calculate Tension in a String With Masses and Friction?

    Homework Statement Two 20 kg masses rest on a horizontal table. The bottom mass is connected to a string of negligible mass, which passes over a frictionless pulley with negligible mass and supports a third 20 kg mass that hangs over the side of the table. The coefficient of kinetic friction...
  11. M

    Velocity of Pulley: Mass 1 & 2, Frictionless Disk

    Question: Mass one is 15.0 kg and mass 2 is 9.0 kg. They are connected by a massless rope which passes over a frictionless pulley. The pulley has a shape of a solid disk. They pulley mass is 8.0 kg and the pulley radius (R) is 0.20 meter. What is the speed of the falling body? Solution: I...
  12. L

    A box attached to a pulley on a ramp

    Homework Statement Mass of box: 27.0 kg mass of bucket attached to pulley: 25.0 kg incline:35 degrees static friction:.650 kinetic friciton: .490 Okay, there is a box on an incline. The box is attached to a pulley. A bucket is attached to the other end of the pulley. The bucket is going...
  13. I

    Solving a Belt and Pulley Question Using Simple Equations

    Hi guys, I am working on a simple belt and pulley question, as pictured below. To find the magnitude, I used the following equation: (g(M-m))/(M+m) So, 9.81(2500-600)/(2500+600) = 6.01 - Answer = 6kN Is this correct, or am I doing it totally wrong? I have searched for the...
  14. A

    Final angular velocity of a mass on a pulley

    Homework Statement Use Newton's 2nd Law, sum of torques, and kinematic equations to determine the angular speed of the spool shown in the figure below. Assume the string has a negligible mass, and it turns without slipping. Use g=10 m/s2 for acceleration due to gravity. Homework...
  15. J

    Find Period of Oscillation for Pulley on Spring - Light & Matter

    Homework Statement A pulley containing only a single mass, m, is hanging vertically from a mass with spring constant k. Find the period of vertical oscillation for the mass. Explanation in terms of energy and energy conservation is preferred.Homework Equations Ay, there's the rub. You are...
  16. N

    Work & Power of Pulley System Homework

    Homework Statement 20 Kg box is raised 0.75m by a constant 25N force applied at the end of the cord if the pulleys are massless, determine work done on the crate. What is the power delivered at the end of the cord at this point? Identical pulley system...
  17. B

    Moving Pulley Mechanics Question

    Homework Statement A string is attached on a pulley, with Mass 1 (2 kg) hanging from the left and Mass 2 (5 kg) hanging from the right. The pulley itself is being pulled upwards with a force of 100N. Find the tension T in the string, and the accelerations of both masses. We consider...
  18. T

    Pulley problem with frictionless ropes

    Homework Statement In the diagram, the pulley is frictionless and the ropes are massless. You are given that m1 = 10.0 kg and m2 = 29.5 kg. Calculate the acceleration of m2 downwards. What is the magnitude of the tension in the string? Homework Equations sum of F= M*A The Attempt at a...
  19. S

    Pulley question about a mass on a string

    Homework Statement i'm having a lot of trouble with this question. A pulley, consisting of a 0.40 m diameter wheel mounted on a horizontal frictionless axle, is firmly attached to the ceiling. A light rope wrapped around the pulley supports a 0.50 kg object, as shown in the diagram...
  20. R

    Force AGAINST a pulley due to tension

    heres the problem and its solution: I understand how to find reactions etc etc, the only thing that i don't understand is how to calculate the net forces that are acting on the pulley. the tension in the line is trying to "straighten" the line out, the pulley is fighting this force to...
  21. C

    Angular acceleration and moment of inertia on a pulley

    Homework Statement Two forces are applied to a pulley with a moment of inertia I = .15kg*m^2. The pulley is mounted so that its frictionless axle is fixed in place. 1) What is the angular acceleration of the pulley? 2) If the pulley starts from rest, how long does it take to undergo...
  22. G

    Conservation of energy and string pulley problem

    Homework Statement Consider two masses of 3.3 kg and 7.4 kg connected by a string passing over a pulley having a moment of inertia 12 g · m2 about its axis of rotation, as in the figure below. The string does not slip on the pulley, and the system is released from rest. The radius of the...
  23. I

    Oscillation of a spring - pulley system

    A massless spring of constant k=196 N/m is used to suspend the mass M=1.45 kg (including the pulley), as shown in the attached figure. What is the frequency of simple harmonic motion? Relevant equations f = 1/period T = 2pi*sqrt(M/k) Tension = 1/2Mg What I tried... T(tension on...
  24. A

    Pulley w/ 3 Masses Homework: Find Linear Acceleration

    Homework Statement An green hoop with mass mh = 2.4 kg and radius Rh = 0.12 m hangs from a string that goes over a blue solid disk pulley with mass md = 2.4 kg and radius Rd = 0.11 m. The other end of the string is attached to a massless axel through the center of an orange sphere on a...
  25. B

    Finding Tension in a Pulley System

    Homework Statement A crate is pulled up using frictionless pulleys in the manner shown in the figure. The angle is 45 degrees. The masses are, for the small pulley, m1=4.1 kg, for the traveling pulley, M2=6.7 kg, and for the crate, MC=45.8 kg. What is the minimum tension with which the...
  26. T

    Two blocks, a pulley, and an inclined plane.

    Homework Statement An 8kg block rests on an inclined plane where theta=37 degrees. The coefficient of kinetic friction on the plane is .23. The 8kg block is connect by a massless, frictionless pully to a hanging 16kg block. The blocks are released from rest. What is the acceleration...
  27. P

    Statics Pulley FBD: Man's Weight on Cable and Pulley System

    Homework Statement A man having a weight of 150 lb supports himself by means of the cable and pulley shown in the figure. If the seat has a weight of 15 lb, determine the force that must be exerted on cable at A, and the normal force the man exerts on the seat. Answers provided by the...
  28. S

    Conservation of energy with a mass and pulley system.

    Homework Statement Two boxes are attached to opposite ends of a rope passing over a frictionless pulley as shown below. The mass of Box A is 15kg and the mass of box B is 12kg. The system is originally at rest with the bottom of box A at a height of o.85m above the floor. When the system is...
  29. M

    Pulley Torque Calculations for Motor with Added Pulley: Is the Torque Affected?

    I think I'm over thinking this, so someone set me straight. If I have an eletric motor with a 75mm OD shaft making 1450Nm of torque, and I add a 7in pulley/sheave to the motor shaft. Would the torque change? Half of me says yes other half of my brain thinks no. Torque = Force *...
  30. A

    How Do You Calculate Acceleration and Tension in a Three-Mass Pulley System?

    Homework Statement The three blocks are attached via a massless, frictionless pulley system, as shown. The frictionless plane is inclined at an angle  = 60 degrees. When released from rest, the 20kg block will start to slide down the plane. Find the tension in the string. The image is...
  31. P

    How Do You Determine the Acceleration and Tension in a String and Pulley System?

    Homework Statement The masses of blocks A,B, and C are 4kg, 10kg and 2kg respectively. Knowing that P=0 and neglecting the masses of the pulleys and the effects of friction, determine a) the acceleration of each block and the tension in the chord. Homework Equations Fnet=ma The...
  32. M

    Why Does the Atwood Machine Equation Deviate from Expected Results?

    Homework Statement I'm currently doing a lab that focuses on a pulley and have got stuck on on part. The goal here is to use the data from the Atwood’s pulley experiment to test the validity of (m1-m2)g=(m1+m2+1/R^2)a. In this equation, take the quantity (m1−m2)g as the y variable and the...
  33. V

    Solving Question 2: Pulley System Challenge

    Homework Statement The question is on the attached picture, it's question number 2! Homework Equations Dealing with pulleys The Attempt at a Solution
  34. T

    How Do Tensions in a Massless, Frictionless Pulley System Compare?

    A mass M in held in place by the applied force F and the pulley system shown below. The pulleys are massless and frictionless. Determine the tension in each section in each section of rope and the applied force F Taking upwards as positve -T1 - F = 0 T4 - T1 - T3 = 0 T2 + T3 - T5 = 0...
  35. S

    Finding mass within a pulley system. Finding coefficient of friction

    Ok so I'm in college upgrading, and doing my physics 20. I have a hand in assignment due Wednesday and I can't for the life of me figure out these two questions. 6. The 4.0kg block shown accelerates across a frictionless horizontal table at 1.5m/s2. Find the mass of object m1 A. 0.61kg B...
  36. A

    Pulley system: 2 pulleys and 3 mass

    Homework Statement Note: My textbook and first language is french, I am sorry if I mistranslated some terms. A friction-less rope goes around the fix pulley A. At one side of the rope, there is a mass M1. On the other side, there is a pulley of mass M2. Another friction-less rope goes...
  37. A

    Understanding Different Accelerations in Constrained Pulley Motion

    could you please tell me how can the accelaration of masses m1 and m2 can be different. i am in a great necessity.so please explain me how can the two strings of the two sides of the lower pulley have different accelarations?
  38. C

    Two masses, frictionless pulley

    Homework Statement Two masses are connected by a light string that goes over a light, frictionless pulley, as shown in the figure. The 8.7-kg mass m1 is released and falls through a vertical distance of h = 1.09 m before hitting the ground. Use conservation of mechanical energy to determine...
  39. G

    Finding Forces and Work in a Pulley System

    Homework Statement Need some serious help with this one :O A box with a weight WA hangs in pulleys ,(see figure 1). Find the force to pull A up with constant speed and calculate the work which the tractive force F produces ( with the movement of s) and also the work and tractive force...
  40. M

    Newton's Laws with a Pulley, with tension, Force

    Homework Statement If F = 8.0 N and M = 1.0 kg, what is the tension in the connecting string? The pulley and all surfaces are frictionless. Homework Equations F=ma The Attempt at a Solution 8-T=2a (2kg block) T - 1cos10? = 1a (for the 1kg block. I got stuck here, the angle threw...
  41. B

    Newton's Laws Homework question involving a pulley.

    Homework Statement John (mass 80) rests on top of a light cube (mass = 0). A light rope passes horizontally from him over the front edge, and vertically down to Brian (mass 60kg) who hangs in contact with the front face as shown. The cube is on a horizontal surface and there is no friction...
  42. A

    Forces: Wedge and Block Problem + Pulley System Problem

    Homework Statement 9) A 15 kg wedge is pushed along a frictionless surface. There is no friction between the wedge and the block. What force, F, is required to keep the block from sliding up or down the wedge? See attachment for diagram. 10) Find the tension, T. See attachment for diagram...
  43. P

    Pulley problem that is most likely easier for you than for me.

    Homework Statement 2 blocks that have the same mass are connected by a string and passed over a pulley. The angle made by the horizontal plane and the ramp is 30 degrees. 1 of the blocks is dangling off the edge of the ramp while the other block is placed on the ramp. If neither block moves...
  44. E

    A pulley system with two objects stacked on one another

    Homework Statement Block B, with mass 5.00kg, rests on block A, with mass 8.00kg , which in turn is on a horizontal tabletop. There is no friction between block A and the tabletop, but the coefficient of static friction between block A and block B is 0.750. A light string attached to block A...
  45. S

    2 Blocks 1 Pulley - First Time Poster

    Hi! First Time Poster. Thank you for helping me with my problem! Homework Statement A 28.3-kg block (m1) is on a horizontal surface, connected to a 5.5-kg block (m2) by a massless string as shown in the Figure. The pulley is massless and frictionless. A force of 208.9 N acts on m1 at...
  46. A

    Pulley but the cable is at an angle?

    Homework Statement http://img813.imageshack.us/img813/594/75309500.png http://img813.imageshack.us/img813/7166/51848816.png I have to find acceleration to calculate how long it takes the heavier box to reach the end of the table. Homework Equations The Attempt at a Solution...
  47. E

    GPE and KE of two unequal masses over pulley

    Homework Statement Two unequal masses are connected by a light cord passing over a smooth pulley. State the gravitational potential energy \DeltaU(> or < or = 0) and the kinetic energy \DeltaK(> or < or = 0) of the system after the masses are released from rest? Homework Equations...
  48. H

    What is the restorative torque applied to the disk in a pulley system?

    Hi everybody, I was doing my physics homework but I found that I cannot figure out how to do it, here is the question: http://imageshack.us/photo/my-images/202/phyl.jpg/" I don't quite understand how to calculate the torsional spring constant, so explanation on part a is enough:D Thanks...
  49. A

    A very difficult question about a pulley system with friction

    Homework Statement See the picture Homework Equations The Attempt at a Solution This is a very difficult, can anyone guide me step by step to finish this question. First, let start with part(a) In order to find the ratio, it seems we need to have the motion equations first...
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