Pulley Definition and 1000 Threads

  1. A

    Torque on a Non-Circular Pulley

    Homework Statement Homework Equations Shown BelowThe Attempt at a Solution I need to find the torque (or even better, velocity) as a function of position. Right now I have mass and centroid (to find the force of gravity on the pulley at any position). Not sure if the mass moment of inertia is...
  2. L

    Question from a non-engineer: Pulley Systems

    Hello from a non-engineer. This post has a very practical purpose: I'm about to move into a small loft apartment with high ceilings but limited living and closet space. I'd like to find some way to mount a pipe to the ceiling via pulleys and rope or cable that can be lowered and raised with a...
  3. L

    Kinetic Energy including a pulley

    Homework Statement Two blocks, of masses M = 2.0 kg and 2M are connected to a spring of spring constant k = 200 N/m that has one end fixed, as shown in the figure below. The horizontal surface and the pulley are frictionless, and the pulley has a moment of inertia I=0.005 kg.m^2 with radius...
  4. M

    How Do You Calculate Forces and Accelerations in a Two Block and Pulley System?

    1. A block with mass m1 is placed on an inclined plane with slope angle α and is connected to a second hinging block with mass m2> m1 by a massless cord passing over a small frictionless pulley. The coefficient of kinectic freiction between mass ma and the incline is negligible. Find: (a) the...
  5. S

    Two Masses in Pulley System (Rotational Dynamics)

    So I've been prepping for my Engineering Physics 1 final, and I've been having trouble with rotational motion problems, but this problem has been driving me crazy for the past two days: Homework Statement (I wanted to include a normal link to an image, but I'm a new member, so here's...
  6. P

    Why are the accelerations of blocks A and B different in this pulley problem?

    It is not actually homework, but a physics problem I have encountered. For ease of discussion, I am attaching the question [University Physics, Young and Freedman, 12th edition] and it's solution as appeared in the solutions manual. What I don't understand is: In section (c), how can the...
  7. W

    Angular Acceleration of a Pulley Supporting Two Hanging Masses

    Homework Statement Hi all! I'm working on a dynamics homework and have hit a wall here: "If the frictional moment at the pivot O is 2 N m, determine the angular acceleration of the grooved drum, which has a mass of 8 kg and a radius of gyration k = 225 mm. Ans: α = 0.622 rad/s^2 "...
  8. B

    Analysing a pulley block system

    A pulley is mounted at the edge of a table. A block is connected to an identical block through the pulley(assumed to be weightless)by a weightless in-extensible thread of length 2l. The left block rests on the table at a distance l from the edge (where the pulley is mounted) while the right...
  9. B

    Find Mass of Box K for 25 Degree Angle in Pulley Assembly | Pulley Question Help

    Homework Statement An assembly shown in the picture, GH , HK, HNL are three cables. the mass of box L is 52Kg, a) determine the mass of box K in order to make angle theta as 25 degrees Homework Equations FX=0 FY=0 The Attempt at a Solution right i started with Fhn x...
  10. V

    Factors affecting how hard a man has to pull on a pulley

    A question has arisen (not homework) showing two pulley systems and a box being pulled up with a man pulling each. The question asks who has to pull hardest. On one of them (A) the shafts (supporting the rope) are smaller whilst on the other (B) they are larger. The correct answer is that the...
  11. I

    Pulley dynamics problem 12-205 Hibbeler

    Homework Statement I have posted the snapshot.Homework Equations I have written the distances from the datum line. Since we have two threads, I got two equations. 2S_A +S_C=L_1 (S_B -S_C)+(h-S_C)=L_2 where L1 and L2 are the lengths of the strings excluding the parts which remain constant in...
  12. B

    Pulley question to determine the weight at a certain angle

    Homework Statement An assembly shown in the picture, GH , HK, HNL are three cables. the mass of box L is 52Kg, a) determine the mass of box K in order to make angle theta as 25 degrees Homework Equations Fx=0 Fy=0 The Attempt at a Solution Fhn x cos(25) = Fhg x cos(0) fhn x...
  13. T

    How to draw pulley system diagram to find the relationship between two objects?

    Homework Statement Here is the diagram and I need to find a relationship between the acceleration in block A and the acceleration in block B. http://dl.dropbox.com/u/64325990/HW%20Pictures/datum2.PNG The Attempt at a Solution Here is my diagram, which is wrong...
  14. R

    Frictionless pulley system: same tension changing masses

    Homework Statement An astronaut lands on a distant planet with an unknown gravitational field g’. On the bottom of his spaceship, he attaches an ideal frictionless pulley supported overhead with two light buckets hanging downwards, attached by a light rope. He places 24 kg of the same rock...
  15. B

    Finding moment of inertia of a pulley

    Homework Statement Two masses, one of m_{1}= 3kg, the other of m_{2}=4kg, hang from opposite sides of a pulley of radius .15m. When released from rest, the heavier mass falls .34m in 4s. What is the rotational inertia of the pulley? Homework Equations Newton's second law and \tau =...
  16. F

    Zipline Diameter Pulley Friction/ Rolling Resistance

    My zipline is 200 feet long built with 7/16" Stainless Steel Cable. Would 3/8" cable result in a faster ride with less noise from the trolley due to significantly less surface area for friction?
  17. P

    Pulley Problem Dealing with Torque

    Homework Statement A 1.53-kg mass hangs on a rope wrapped around a frictionless disk pulley of mass 7.07 kg and radius 66.0 cm. What is the acceleration of the mass? I know this has been posted before but I learn better when I try to solve things on my own. Homework Equations F...
  18. K

    Pulley, Ramp with Moment of Inertia

    Homework Statement http://imgur.com/ZkjXv The given answers are (b) .309 m/s^2 (c) T1= 7.67N, T2=9.22N Homework Equations I_disc = .5(mass_disc)r^2 Sum of Torque = I α a = r α The Attempt at a Solution We will define the system moving right and down as positive to get a positive...
  19. S

    Pulley Small or Large for a Motor

    A motor can't lift a pale of water for given diameter of pulley. (consider the motor directly connected to the pulley). So, the diameter of the pulley should be Increased or decreased? Why?
  20. E

    I=mv^2/w^2-2mgh/w^2Find Inertia of Wheel for Block & Pulley Homework

    Homework Statement A block of mass m=2.4kg is attached to a string that is wrapped around the circumference of a wheel of radius r=7.6cm. The wheel rotates freely about it's axis and the string wraps around it's circumfrence without slipping. Initially, the wheel rotates with an angular...
  21. J

    Conservation of momentum in pulley

    Two blocks of mass m connected by a light string passing over a pulley. Say, one of the blocks is pushed downwards with a force F and it attains velocity v.So the other block moves upwards with the same speed v right? Total moementum = mv - mv = 0( because one is moving upwards and other...
  22. 3

    Transverse waves on pulley - question

    Homework Statement 1) an aluminium wire, of length L1 = 60.0 cm, cross sectional area 1.00 x 10^-2 cm^2, and density 2.60 g/cm^3, is joined to a steel wire of length L2, of density 7.80 g/cm^3 and the same cross sectional area. The compound wire, loaded with a block of mass m = 10.0 kg, is...
  23. J

    Why Is There a Reaction Force in the Upper Pulley but Not in System 1?

    Homework Statement m(1) is 20kg m(2) is 30kg gravity use 10 U static is .6 u kinetic is .4 Homework Equations Basically my professor gave the answer to the question in the link along with the picture. The only problem is that i am not sure he did case three right and i am after...
  24. Z

    Which pulley system requires the least force to lift the same weight?

    Homework Statement http://data.imagup.com/10/1146555432.jpg Homework Equations Force applied on the weight=F*(MA). The Attempt at a Solution i chosse the E system ...it has the greater mechanical advantage (MA)=3. MA(of A)=1, MA(of B)=2,MA(C)=2,MA(D)=2,MA(E)=3.. I hope my...
  25. A

    How Does Friction Affect the Acceleration in a Pulley System?

    Homework Statement A system comprised blocks, a light frictionless pulley, and connecting ropes is shown in the figure. The 9.0-kg block is on a perfectly smooth horizontal table. The surfaces of the 12-kg block are rough, with \mu_k = 0.30 between the block and the table. If the 5.0-kg...
  26. D

    HELP Find the mass in this inclined pulley system, required to move the 2 masses

    In this problem they show a diagram of a pulley system with an inclined plane (25 degree incline). There is a box called m1=47kg resting on the incline plane and m1=35kg hanging on the vertical line. The question reads: The coefficient of friction between m1 and the surfvace of the inclined...
  27. T

    1 pulley, 2 masses, 2 inclines

    Homework Statement Calculate the tension in the cable connecting the two masses. Assume all surfaces are frictionless. in lieu of the picture here are the given specs: on the left side a 5 kg mass with a 60' incline on the right side a 6 kg mass with a 70'incline Homework Equations...
  28. A

    Two boxes connected to a string over an ideal pulley?

    Homework Statement Two blocks are connected by a string that goes over an ideal pulley as shown in the figure and pulls on block A parallel to the surface of the plane. Block A has a mass of 3.00 kg and can slide along a rough plane inclined 30.0° to the horizontal. The coefficient of static...
  29. U

    Rope with mass but ignoring Pulley

    If there is a problem like in the image provided, and the rope has a mass but the pulley is not being considered in the problem, what forces would the rope affect the man with? Since the rope touches the ground will the rope send a normal force up which pushes the man up? I am assuming that...
  30. G

    Two radii pulley lifting a pack

    Homework Statement You are pulling on a rope attached to the outer radius of a pulley with a moment of inertia I=676 kgm2 as shown. The tension in the rope that you are pulling is 477.9 N. A pack of mass 30.8 kg is attached to the pulley's inner radius as shown. If the inner radius of the...
  31. F

    Simple lab with two blocks and pulley

    Homework Statement I have 2 blocks. M1 is resting on a horizontal plane and attached to a string that goes over a pulley to M2. The plane is like an air hockey table to simulate very little friction. I attached spark tape to M1 so I could measure the time it took and distance traveled. Now...
  32. W

    Forces in equilibrium. Tension, ring, pulley and lots of string [With Picture]

    Homework Statement To make it easier on the people who will try to help me, I've scanned the problem: We are interested in finding the following variables: Angles a and c The tension between A and B (TAB) Homework Equations The pulley is a "perfect pulley" no friction The system...
  33. F

    Dynamics midterm coming up don't understand pulley questions

    Determine the speed of the elevator if each motor draws in the cable with a constant speed of 5 m>s. Here is a link to the question and diagram. Scroll down to page 154. Its question 12-199. http://www.mem.odu.edu/~bawab/ME205f/hwk12.pdf I don't understand how to get the distances. Any...
  34. S

    Will a 1 HP Electric Motor Match My Log Splitter's Performance?

    RPM to Pulley Question Please Help Thanks! I have a log splitter that uses a gas engine 3600 RPM the drive pulley is 1.5"OD diameter and the driven pulley is 18.25" diameter (Super Splitter is the brand name) So from what i calculated was the driven pulley weighs in at 75lbs and spins at about...
  35. J

    Dynamics: Determining amount of energy dissapated by a pulley

    Homework Statement Blocks A and B have masses 11 kg and 5 kg, respectively, and they are both at a height h = 2m above the ground when the system is released from rest. Just before hitting the ground block A is moving at a speed of 3 m/s. Determine a.) the amount of energy dissipated in...
  36. T

    Work-Energy problem involving pulley

    Homework Statement The system shown is at rest when a constant 250N force is applied to block A. Neglecting masses of pulleys and friction, determine: a) Velocity of block B after block A moved 2 m. b) The tension in the cable http://imageshack.us/photo/my-images/259/photoivl.jpg/...
  37. C

    Work done by motor with pulley wheel on spindle.

    I need to calculate the work done by an electric motor when it has a pulley wheel on the end but nothing on the pulley wheel. I know work done = force x distance. And of course force = mass x acceleration. But I cannot for the life of me think of how I am going to work out the acceleration? or...
  38. J

    What Is the Minimum Mass Needed to Move the Block in a Pulley System?

    Homework Statement A block with mass, m1 = 5.5 kg rests on the surface of a horizontal table which has a coefficient of static friction of μs = 0.52. This block is connected to another block by a pulley system and it hangs vertically under the influence of gravity, g. The hanging block has...
  39. T

    Acceleration of a car pulled by a block falling (pulley)

    Homework Statement A car and pulley system are setup as shown. Find the acceleration of the car. The car wheels have a friction coefficient of 0.15. The car has a mass of 0.05 kg while the block has a mass of 0.02 kg. http://sadpanda.us/images/836771-GBD7SB9.jpg *sorry if the picture is bad I...
  40. G

    Solve ODE Pulley Slippage: Find Tension w/ μ = 0.2

    Homework Statement The slippage of flexible belts over shafts or pulleys of circular cross sections is an important consideration in many mechanical devices. When the frictional contact between the belt and the shaft is about to be broken (that is when the slippage is imminent), a belt drive...
  41. F

    Understanding the Effects of Force on a Pulley System

    Homework Statement Two blocks of mass m1 and m2, resting on a frictionless tabletop, are connected by a massless string passing through a frictionless pulley of mass mp. The figure shows a top view of the arrangement. If a force of magnitude F is applied to the pulley in the direction...
  42. K

    Three objects on a hanging pulley system

    Homework Statement Three objects with masses m1 = 37.5 kg, m2 = 19.5 kg, and m3 = 11.1 kg are hanging from ropes that are redirected over pulleys. What is the acceleration of m1? Negative numbers for downward, and positive numbers for upward, please. There should be a diagram of what the...
  43. D

    Bending around sheave or pulley

    I need to calculate how much tension it would require to bend large insulated cable of various sizes around a pulley. The Conductor would be made of aluminum or copper and solid. The Insulation would be of various thicknesses depending on the cable. I was looking at breeaking this problem down...
  44. T

    Solving Massless Pulley: Finding Accelerations, Tension & Pulley Motion

    Homework Statement m1 and m2 are connected by a massless string wrapped around a massless pulley. An external force F is applied to the pulley. m1 does not equal m2 find the acceleration of each mass, the tension in the string, and the acceleration of the pulley. F external and m1 and...
  45. S

    Finding tension and acceleration in a 3 weight, 3 pulley system

    Homework Statement This is a "DOE" (Design of Experiment) problem. Basically, the construction is fairly simple. 3 pulleys, 2 on either side, and a free pulley with a weight suspended on it in the middle. Picture is available (don't mind my crappy paint skills, rope lengths are all...
  46. M

    Double Pulley Systems/Complex Pulley System Problems

    Hey.. This is a question I received as part of my homework Your great grandmother gave you an antique scale that her great grandmother gave to her. It consists of a square platform mounted on 4 identical springs. When you step on the platform, you compress the springs, causing the platform...
  47. S

    Static Equilibrium Pulley and free body diagram

    Homework Statement Attached is the picture of the problem and my free body diagram. The system is in equilibrium. Homework Equations Fy = 0 Fx = 0 The Attempt at a Solution I'm having trouble solving the two equations that I arrive with... I use +x to the right, and +y up...
  48. P

    Physics problem with masses and pulley and a ramp

    Homework Statement 2 masses m1=50g and m2=5g are connected as shown (sori walang pci) m1 is free to move along a horizontal frictionless table. Neglecting the mass of the cord connecting the two masses and assuming a frictionless pulley. Determine the accelereation of the system of blocks...
  49. B

    Max weight that anyone can lift using over head pulley.

    Can a man whose weight is 50KG (but powerful arms) lift another man with 70 KG weight using an overhead pulley. I guess no since the light man is not clamped to the groud, his arm strength will not bear any significance and he can lift only the wieght(on other side of the pulley) equal to his...
  50. D

    System of particles passing over a pulley

    1. Homework Statement Two particles of masses m1=8 kg and m2=5 kg are connected to the two ends of a light inextensible string which passes over a fixed smooth pulley. Initially each of the two particles are held at a position which is 5 m above a horizontal ground. The objects are then...
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