A pulley is a wheel on an axle or shaft that is designed to support movement and change of direction of a taut cable or belt, or transfer of power between the shaft and cable or belt. In the case of a pulley supported by a frame or shell that does not transfer power to a shaft, but is used to guide the cable or exert a force, the supporting shell is called a block, and the pulley may be called a sheave.
A pulley may have a groove or grooves between flanges around its circumference to locate the cable or belt. The drive element of a pulley system can be a rope, cable, belt, or chain.
The earliest evidence of pulleys dates back to Ancient Egypt in the Twelfth Dynasty (1991-1802 BCE) and Mesopotamia in the early 2nd millennium BCE. In Roman Egypt, Hero of Alexandria (c. 10-70 CE) identified the pulley as one of six simple machines used to lift weights. Pulleys are assembled to form a block and tackle in order to provide mechanical advantage to apply large forces. Pulleys are also assembled as part of belt and chain drives in order to transmit power from one rotating shaft to another. Plutarch's Parallel Lives recounts a scene where Archimedes proved the effectiveness of compound pulleys and the block-and-tackle system by using one to pull a fully laden ship towards him as if it was gliding through water.
Homework Statement
http://imgur.com/ymNWTOV
Image isn't working, here is the question:
http://imgur.com/ymNWTOV
Homework Equations
F=ma
Weight force=mg
Frictional force=μkN
The Attempt at a Solution
So for part (a):[/B]
Force on 10kg block=mg=10x9.8=98N
This is equal to the tension force in...
Homework Statement
So I have a horizontal pulley positioned at the edge of table with a mass of .2kg hanging down from a height of .76meters, the other end of the string is attached to a wooden block of mass .25kg that when the .2kg weight is dropped the wooden block is pulled towards the...
Homework Statement
The problem is asking to find the volume of this pulley
Formulas that is in the chapter.
Area = r^2*θ/(2)
Where θ is in radians
Homework Equations
I drew the drawing in solid works and got the volume to come out to 6.27 cubic inch. But I am not sure if this is the correct...
Homework Statement
A monkey which has a mass of ##m## is hanging on a rope as the picture shows. Then the monkey starts to move upwards with speed ##u##. Find how the box which has a mass of ##2m## will move. Neglect friction between the rope and pulleys. Assume that pulleys are massless...
Homework Statement
Ringling Brothers Bamum and Bailey Circus is using a pulley to lift an Elephant on to a ship. If the Elephant is 2200kg and you have to raise her 15m with a pulley that has an efficiency of 60%, then how much rope do the handlers, who can pull with a combined force of 115 N...
Homework Statement
Given that a weight m1 is attached to a string going over a perfect pulley attached to another pulley suspending weight m2, and that weight m1 is on an incline with an angle of 37 degrees, find acceleration, tension, which mass hits the ground first, time needed to hit the...
Hi all, first post here. I'm a junior Physics/Math double major at UMass Amherst, playing with some problems over the summer. I'll get right into it.
A rope with constant tension T is deflected through the angle 2\theta_{0} by a smooth, fixed pulley. What is the force on the pulley?
It is...
Homework Statement
Homework EquationsThe Attempt at a Solution
When the particle of mass M/2 collides with the pan ,an impulsive tension acts on the (pan+particle) . Let us call this J . Tension acting in the string between the two blocks is T .
Speed of particle before collision = u =...
https://auddoq.dm2302.livefilestore.com/y2mGb2n5mfKxwU4nZlLmOvyElgDcG0-5GG9dGoP4AbrV1taK31XrOoPmeyf9x9RQZ8kXLi0WG2Etd0-I8bVWqOgVufahONs02hTGFS-SUwBVRyd-ajz5Eza-nrk9yWa7kF6kPFtMdPD6MGIpfwQMhywCLfOOuIO4-3tLe1_KjSf9V0/20150505_234057356_iOS.jpg?psid=1
if the image does not show here's the link...
For example, a 1-m bar fixed to a wall holding a weight of 100 N, like this:
How will the free body diagram of the second case different from the first?
Homework Statement
Homework Equations
a=Rα
The Attempt at a Solution
Free body diagrams:
For larger pulley, TR=Iα ⇒ T=½MRα
If this pulley rotates by some amount suchat x length of rope becomes free, and if I hold the smaller pulley at rest, then this extra length of rope comes bellow the...
Homework Statement
Hi all,
I just had a quick question regarding a problem that I have to write a lab report on. The problem involves solving for the moment of inertia of a system that involves a pulley with a hanging mass attached to a spool that turns a flywheel. The solution is supposed to...
Hello,
My friend needs to transfer construction objects across a pond, came up with this idea of tying a rope between the pond and a big tree then transfer objects through a pulley, I'd like to know how to calculate the tension and will the thin concrete wall withstand the load? Here a diagram...
Dear friends, I am a naval modelist and as i am retired due to health problems I use my project ob building a sail boat model as a red line to learn about the diverse technologies I am confronted on this path. So my goal is not that of finishing the project of my sail boat, but to learn ans...
Homework Statement
Find the acceleration of the system if the mass m1 is a disk with radius R rolling down an incline which makes an angle theta with the horizontal, and the disk is connected to a pulley with mass M and radius R, which is connected to a block m2 hanging from that pulley. The...
Homework Statement
A 16 kg mass is suspended from the end of a rope around a 22 kg cylinder with a 6.0 m diameter. What torque applied to the drive axle of the cylinder is required to accelerate the 16 kg mass 2.0 m/s^2 upwards?Homework Equations
Torque = Radius cross Force
The Attempt at a...
Homework Statement
Homework Equations
Kinetic Energy = 0.5 I w^2
v = r * w
torque = Inertia * angular acceleration
The Attempt at a Solution
That's the problem. I have no idea where to start. I assume that the end goal is to find the angular velocity, and convert to linear velocity, but I...
Hi all,
I have a small DC motor which turns at 20 rpm. The shaft diameter is 6mm, giving a circumference of 18.85 mm. What I want to do is get an effective rate of 30 rpm. Can I do this by simply attaching a spool or spindle to the motor output shaft with a larger diameter? If so, would it...
Homework Statement
Given: T(sub-B) plus T(sub-B) prime = 36. Both T(sub-C) values are 0. T (sub-D) =36 and T (sub-D) prime = 12. Find values of T (sub-B) and T (sub-B) prime[/B]Homework Equations
OK, so we need to find the wrap angle, which should be 180 + 30 -22, which comes to 188...
Homework Statement
A 10 kg mass is on a frictionless inclined plane 30 degrees to the horizontal. At the top of the plane is a pulley that has a rope attached to mass with tension T = 75 N. If the mass starts from rest, what is its velocity after 2 seconds?
Homework Equations
F = ma
Vf=Vi +...
Homework Statement
A spring is attached to the ceiling, a pulley is attached to the other end of the spring, a string is suspended over the pulley, and a mass attached to the free end of this string. The system oscillates vertically.
Can someone PLEASE help me derive this equation for natural...
Homework Statement
Hi, I encountered a problem whilst doing problems involving transverse waves. If somebody could give me a pointer I would appreciate it. The question is:
"One end of a horizontal rope is attached to a prong of an electrically driven tuning fork that vibrates the rope...
Homework Statement
The pulley in the figure has radius R=0.160m and a moment of Inertia I_p = 0.560 kg*m^2. The rope does not slip on the pulley rim. As m_4 (4kg block) drops due to gravity, m_2 (2kg block) is dragged up a ramp inclined at theta = 65 degrees. The coefficient of kinetic friction...
Problem: Find the acceleration of the blue cylindrical disk. Both, red and blue, cylinders have same mass and radius, and string is massless.
Attempt: Identified three equations: one for linear acceleration of blue cylinder, and two of angular accelerations (one each for blue and red...
Homework Statement
Homework Equations
F=ma, Fr = μN
The Attempt at a Solution
1kg(1m/s^2) = 1N
Fnet = (x) - 1.18
1N = x - 1.18
x = 2.18N
2.18N/9.81m/s^2 = 0.223kg
I know this is not right because I was told that in my calculations Fnet and Fr go in the same direction. Also I didn't use...
Hello everyone. This is my first post on here. I figured that I would give it a shot. Just as a quick background:
I'm studying electrical engineering and I'm working an internship for a machine manufacturing company now. One of the projects I have been assigned is to come up with a system to...
Hi I am new to this site, I'm currently studying my Engineering Foundation degree and I am massively struggling on the theory side to pulley tensions. Please could anybody point me to some sites or some information which would help me understand and answer this question in detail.
I have not...
Homework Statement
The system of 2 spheres is in equilibrium. Figure: . If the weight of the second sphere P2=20N, ABC=60 degrees and BAC=30 degrees, find the weight of the first P1 and the force that is applied on the drum of the pulley.
Homework Equations
P1=m*a
The Attempt at a Solution...
Homework Statement
Two masses are connected by massless and frictionless pulleys and string. The coefficients of friction are µs = 0.35 and µk = 0.25 between mass m1 and the table. The masses are m1 = 8.0 kg and m2 = 8.0 kg.
Find the acceleration of each mass and the tension in the string...
Suppose we have a weight D (1 Kg) hanging from a pulley on a rope connected to a wall A
suppose also the distance AB from the wall is 1 m.
If I hung a weight C =1 kg as a counterweight and the pulley were not connected to the wall, the length of the rope BD (1) would equal the length of the...
Homework Statement
In the system shown, the block M (mass of 15.65 kg) is initially moving to the left with a speed of 3.4 m/s The mass of m is 8.26 kg and the coefficients of friction are μs=0.411 and μk=0.304. The string is massless and the pulley is massless and frictionless. How fast will M...
Homework Statement
Part C:
http://imgur.com/mFlXGZs
Homework Equations
Power = τω
The Attempt at a Solution
P1/P2 = τ1ω1/τ2ω2 = (T1/T2) * (ω1/ω2)
T1/T2 is found in part B: r1/r2
(ω1/ω2) = vr1/vr2 (velocities are the same) = (r1/r2)
(r1/r2)*(r1/r2) = (r1)^2/(r2)^2
The answer is 1.
We're given a problem: A 2.0 kg mass hangs from a rope attached to an unknown mass m on a frictionless ramp inclined at 20 degrees above the horizontal. This is drawn as a diagram which shows the incline at 20 degrees where the hanging mass is 2.0 kg and the attatched mass on the frictionless...
In this derivation (see attached image), does the author assume that the rope doesn't slip? Because if it does, then there is no guarantee that ##\ddot{l} = 0##, right?
Also, does this equation apply to all pulley systems where one pulley is fixed and the other is allowed to move? For example...
Homework Statement
Two masses are connected by a string that hangs over a frictionless pulley with mass 8kg, radius .25m, and moment of inertia .5mr^2. One mass lays on the ground and has mass 15kg. The other mass is 22.5 kg and is 2.75 m above the ground. Use conservation of energy to...
Homework Statement
For what m1 will the illustrated pulley system be in static equilibrium if m2 = 60 kg?
Homework EquationsThe Attempt at a Solution
im supposed to use the change in lengths but don't know how to do it
Homework Statement
1. Pulley B is free to move on the cable ABC which is fastened at A and being pulled by force F through the pulley C. Neglecting friction:
a. Determine location of point B as a function of d.
b. Express the force F required to maintain equilibrium in terms of P...
Homework Statement
A cable of length L and mass density λ is rolled on a pulley of mass m and radius r, with its tip hanging. The cable starts to unravel and fall due to gravity; the system starts from rest. Assume the cable has negligible thickness and rolls without slipping on the pulley...
1. Homework Statement
I am stuck on this problem involving tension, acceleration of a system, friction and a pulley. I have an idea of how to find the acceleration of the system neglecting the mass of the pulley, but it is not the solution. How does adding a frictionless pulley in the system...
Homework Statement
Block A in the figure has a mass of 5.00kg , and block B has mass 12.0kg . The coefficient of kinetic friction between block B and the horizontal surface is 0.25.
What is the mass of block C if block B is moving to the right and speeding up with an acceleration 3.00m/s2 ...
Hi, I am new here!
1. There is no actually data given, I am just supposed to explain why a string that crosses a pulley have the same tension both sides. The pulleys moment of inertia is zero and friction is negligible.
There is a little hint in this problem that says; study equation 9-15...
Homework Statement
A massless rope is attached to Block A, which as mass m_A and rests on a horizontal surface with coefficient of kinetic friction u_k. The rope passes over a frictionless, massless pulley and Block B is attached to the other end. When the blocks are released, Block A moves to...
Homework Statement
Hi Guys,
I am looking at a simple movable pulley system like the one two in from the left. I am trying to work out the relationship between the force applied to the free end (called F2 in the picture) and the tension in the cable
Homework EquationsThe Attempt at a Solution...
Homework Statement
In the figure (Figure 1) each of the suspended blocks has weight w. The pulleys are frictionless and the ropes have negligible weight.
Homework Equations
w = mg
Forces cancel out, so Tension = weight (since they are suspended)
The Attempt at a Solution
For a (pulley) )...
Homework Statement
A block of mass m1= 3.70 kg on a frictionless plane inclined at angle θ=30.0° is connected by a cord over a massless, frictionless pulley to a second block of mass m2=2.30 kg. What are (a) the magnitude of the acceleration of each block, (b) the direction of the acceleration...
The force F pulls upwards two masses, m1 and m2(m2>m1), which are connected to each othet via a massless pulley. The masses are perched on the ground before movement starts.
A. What is the acceleration of each one of the respective masses in each of the following situations:
1)F<2*m1*g...
Hi,
I am building a simple pulley for a weightlifting machine. In most cases pulleys are designed to lift heavier loads easier, I want to actually make it harder to lift the load… So I don't have to put so much weight on the end.
Can I amend my simple pulley design in a (simple) way to...
A girl stands on a platform and pulley system. The masses of the platform, girl and pulley are M, m and u respectively. The rope is mass-less. Let the girl pull up on the rope so that she accelerates a upwards. What is the tension of the rope? What is the normal force between the person and the...