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.
Mass 1 = 10.0 kg
Mass 2 = 3.00 kg
The pulleys and rope are massless, and there is no friction.
What is the tension in the rope?
What is the acceleration of mass 1?
If my thinking is correct, the tension is half the weight of mass 2 (14.7 N), and the acceleration of mass 1 is 1.47...
Hi, could someone please verify my answer? Thanks.. :smile:
How many 4-letter words can be made from the letters of the word PULLEYS? Explain your answer.
There are two mutually exclusive cases by which four letter-word can be arranged from the word PULLEYS. Let n(A) be the number of...
Hello,
I have a physics problem most of the way worked out, but i can't seem to get the answer right. I have the problem attached to the post, so hopefully it can provide some insight to my problem.
So far i have:
(Mass A)(gravity) - (Tension 1) = (Mass A)(Acceleration)
(Mass...
Question: http://img486.imageshack.us/img486/5593/pulley9dm.jpg
Ok so i understand that for every moveable pulleys you multiply the mechanical advantage by 2. In this scenario there are 3 moveable pulleys, and they all look like they are supported by the ceiling so I need to divide the load...
The block with mass m2=0.50kg is found to have a speed of 0.30m/s after it has dropped 0.80m. how large a (kinetic) friction force retards the motion of the block with mass m1=2.0kg?
(side note from teacher)
To solve this problem, you can use a string constraint. the total length of the...
I have attached a picture of what I am describing below (Edit: also a link if the attachment didn't go through):
http://img368.imageshack.us/img368/949/mech036fig012zi.jpg
If a mass m1 sits on top of a frictionless table (assume the pulley is as well), attached to a massless string with...
alright, so I was searching for a physics problem, and i came upon this http://www.fearofphysics.com/Probs/mech041.html .This is exactly the problem I was looking for, except, rather than you providing the angle, you are provided with the coeffifient of friction (.620) , as well as the 2 weights...
This is my problem:
A 28 kg. block is connected to an empty 1.00 kg. bucket by a cord running over a frictionless pulley. The coefficient of static friction between the table and the block is 0.45 and the coefficient of kinetic friction between the table and the block is 0.32. Sand is...
a 27.5kg box is connected to a 13.75kg box on a frictionless pulley. my question is if you calculate the acceleration does that include horizontal and vertical acceleration, and if so, how do you just find the downward acceleration?
A block of mass m_1 is attached to a massless, ideal string. This string wraps around a massless pulley and then wraps around a second pulley that is attached to a block of mass m_2 that is free to slide on a frictionless table. The string is firmly anchored to a wall and the whole system is...
I am in Japan and recently acquired a salvage high pressure (500 psi) air compressor. It was junked because the large spoked flywheel v-pulley on the compressor had broken. The pulley is cast iron, about 15", double V belt, keyed shaft about 1.25'.
Could you suggest a source for a...
Does a pulley have more efficiency if it has just one of those cirgular thingies
http://upload.wikimedia.org/wikipedia/en/8/8f/Pulley_class2.PNG
or more
http://www.kirkwood.k12.mo.us/parent_student/khs/BartinJ/four_pulley.gif
An explanation would be helpful as well.
I've attached a picture of the problem I am referring to.
The pulley is placed so that the string makes a 45.0-degree angle with the beam. The beam is uniform, 5.00 meters long, and has weight w_{b}. The professor stands 2.00 meters from the pivot point and has weight w_{p}.
First, I am...
Ok, if you had a question where a cart (m1) is resting on a surface, and is attached to a string passing over a frictionless pulley, off of which another mass (m2) is suspended in the air, what is the equation that I use?
It is like an atwood machine, except m1 is on a surface, and, I need to...
Construction worker Fred, who has a mass of 96 kg, stands on a girder. He sees a sandbag of mass 33 kg sitting on the ground, a distance 12 m below. A massless rope tied to the sandbag runs up and over a frictionless pulley connected to the girder. "Aha!", says Fred, "I'll lower myself to the...
I have a question where there's two masses attached to a pully that has a radius of 5 cm. one mass is heavier than the other one and the first part of the question is asking you to find the acceleration of the mass that's falling (it falls 75 cm in 5 sec). Now the way that i figured it should...
appreciate if Sum1 can help
Two Blocks and Two Pulleys(Other answer didn't include T?)
A block of mass m_1 is attached to a massless, ideal string. This string wraps around a massless pulley and then wraps around a second pulley that is attached to a block of mass m_2 that is free to slide...
Now I am supposed to find the magnitude of the vertical acceleration of mass 1, in terms of mass 1, gravity and the tension.
I found that a_1= ((m_1*g)-2T)/2m_1 but that isn't right. Any help would be great
I have to design a lab to support that F=ma. we are using masses and pulleys but I'm not sure how to set this experiment up. anyone got any ideas? :confused:
thanks in advance 4 any help u can give me
sarah
Rope, Pulleys... and Lots of Tension!
hey,
For the following problem a picture is really needed so I tried drawing one on Paint and uploading a bitmap file ut it said that it was too large...
A 7 kg monkey climbs up a massless rope that runs over a frictionless tree limb and back down to...
Could somebody please help me with this problem? I am very confused with calculations for multiple pulleys, especially those with movable ones...
http://www.geocities.com/cdy12/pulleys.jpg
I am supposed to find the tension forces T1 and T2, as well as the acceleration of both masses.
I...
hie everybody, this is my first post on this interesting site... :biggrin:
i am not sure how do i count the amount of force needed to turn such a pulley from the spindle attached to the dowel through the spindle. the pulleys are fixed to the dowel and are not movable. they just turn as the...
2 separate ropes A and B and 2 pulleys 1 and 2 are assembled together with 2 masses as shown. puley 1 is supported by rope B and each rope is tied seperately to the heavier mass. Assuming ideal ropes and pulleys, what are the acceleration of each mass?.. (M moves 3 times as fast as 2M)..
the...
Alright, I know I have this stuff somewhere at school, but unfortunately, I can't leave it till tom.
A mass is at rest on a horizontal plane, and is attached by a second mass that is threaded through a pulley and is suspended in the air. What is the coefficient of friction?
The formula...
clarify this for me...
I know that pulleys reduce the work needed, depending on how its setup... But let's say at you add n number of pulleys to mass... And the work is reduced by 1/n... So you add infinite amount of pulleys... and then you supply an infinity amount of force... inf/inf = ...
Hi, for all !
could any of you help me to understand the velocities on cables linked to pulleys. Please, see the attached problem.
thank for all of you,
Leonel
You have a puley on which a light string passes. At one end ofthe string a mass of 5 Kg is attached and on the other end another pulley of mass 1 Kg is attached. A second light string passes over this second pulley. At the extremities of this string two masses of 2 and 1 Kg are attached...
There are 3 blocks on a table. One of the blocks, block C, is in the middle of the table with mass 2M. There are two pulleys on the edges of the tables. The pulley on the left is attached to block C and is attached to block A (which has a mass of M) such that it is hanging off of the pulley and...