A block and tackle is a system of two or more pulleys with a rope or cable threaded between them, usually used to lift heavy loads. ) Pulley B C. Start studying Combo with Simple Machines , pulleys, and levers. Snub Pulley – A conveyor pulley used to increase belt wrap around a drive pulley, typically for the purpose of. ) Not enough information to decide. 2 – Connectors. If you remember, there's a hard way to do this, and an easy way to do this. Attach pulley securely over the top of the door. The last type of simple machine is the pulley. Pulleys are used for exercise, especially in hospitals, to help patients grow stronger. The 40-lb block is moving downward with a speed of 3 ft/s at t=0 when constant forces P and 2P are applied through the ropes. When he's finished reading, help him brainstorm some examples of pulleys that we use in everyday life!. Pulley Problems On this page I put together a collection of pulley problems to help you understand pulley systems better. A simple example of this consists of a pulley, groved to accommodate the rope, top and bottom with a rope threaded round as shown. When the pulley is pulled on one side, the wheel turns, which will move. Pulley diameter ™ ‚Optimization examples of the pulley size ™ 1 Calculate: Resultant R SPECIFY THE RESULTANT LOAD OF THE PULLEY The resultant load R is specified on the basis of the belt tensions. What do you understand? What is still confusing? Meet with your group to discuss materials for the classroom machine building contest. Tail pulleys commonly serve the purpose of a Take-Up pulley on conveyors of shorter lengths. When the truck is next to the bus you feel that as you go backward to the west or when the two cars have same velocity when you look another car you feel you do not move. plural form of pulley. Another use of the pulley is with a flat wheel and belts. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician. Make your own pulley system at home. The following are a bunch of pulley exercises and problems. 81 m/s 2) / ((0. A pulley can also be attached to a fixed point and move an object horizontally from one place to another like on a zip line. If the pulley has a mass of a few grams, this could be significant. How to Calculate MA of Simple Machine of Pulleys The effort needed to lift a load can be halved by using two pulleys: one fixed and the other moving. Available from stock in many common sizes, or custom made, Dodge Heavy Duty drum pulleys meet and/or exceed CEMA (Conveyor Equipment Manufacturers Association) application standards for use with conveyor belts rated up to 750 PIW (Pounds per Inch of Belt Width) / 131 kN/m. Below you will find examples of each. Given the mass of both objects and distance of motion, the student must determine the work…. Movable Pulley; When the block of the pulley is not fixed but carries the load, it is known as Movable. Buy pulley and sheaves for electric motors at discount prices. The pulley is one of the six simple machines. The stresses in a pulley connected to an engine that drives another pulley are studied in this model. It's easier to pull than to lift. The bucket moves up and the block moves down. Other moving parts: all parts of the machine which move while the machine is working. This heavy duty gambrel and pulley hoist system gives you the power to hoist large game, equipment or machinery up to 440 lbs. tensioner pulleys has earned them a reputation for quality long lasting performance. Attention! Always insert the connector. A pulley system is when you combine two or more pulleys. levers, pulleys and gears, allow a smaller force to have a greater effect. It is a system of two or more pulleys. Learn about pulleys with this interactive video lesson on pulleys, for kids. Simple Machines - Practice Problems Name _____ A crate of bananas weighing 3000 N is shipped from South America to New York, where it is unloaded by a dock worker who lifts the crate by puling with a force of 200 N on the rope of a pulley. While the physical system is somewhat more complex than the original, 2-pulley. For this pulley system, only the first picture shows the entire system, but due to its size, it is not clear. Jun 28, 2019- Reeving blocks to set up a double pulley system requires a little thought. A fixed pulley consists of a wheel fixed to a shaft and is used in conjunction with a belt to transfer energy to another fixed pulley. I purchased the California Umbrella 9' Wood Pulley Open Market Umbrella from Edenburg Bunk Bed by Zoomie Kids with Bunk Loft Beds in March 2015 and it broke in Mid-April 2015. Example: the mechanical advantage of a pair of scissors is the product of its 2 levers and 2 wedges. PVC PULLEYS which have a centre insert giving a choice of axle hole of 3mm or 10mm. They make it easier to: · Lift a heavy weight · Move a heavy object · Push things apart. There are after all easier ways to do everything and science has empowered us. It acts to change the direction of a force applied to the cord and is chiefly used (typically in combination) to raise heavy weights". Enjoy the video!. In belt drive, pulleys are affixed to shafts at their axes, and power is. Mechanical Advantage sets for Arborists. Its job is to change the direction of pull on the rope. Levers Pulleys and Gears Differentiated Lesson Resource Pack contains: T2-S-374-Levers-Pulleys-and-Gears-Task-Setter-Powerpoint-Activity-Pack. The third type of pulley is. The differences between them are determined by the location and number of wheels, and the attachment of the wheel and rope. Suppose rod AB is hinged to a fixed wall. Write down the length of each rope in terms of the position coordinates. ) Pulley A B. Volleyball Net Demo/ Flagpole 3. The unit of force is the Newton (N), and a force of 1 N is defined as the force that when applied to an object with a mass of 1 kg, produces an acceleration of 1 m/s 2. ) In reality, there is some friction. Pulleys perform two distinct functions in mechanical advantage systems. One pulley enables you to change the direction in which a force acts. Gears, pulleys and levers A presentation to introduce children to everyday examples of gears, pulleys and levers. Classification of anatomical pulleys There are four classes of pulleys, the first three of them are examples of fixed pulleys and the fourth one is an example of a movable one. There are many different types of pulleys. Pulleys and rope pulley systems for rescue, mountain climbing, arborists, fire fighters, rock and tree climbers and industrial rope access professionals. Other Examples. We provide pulleys optimized for engagement transmission. Timing Pulleys Tsubaki Timing Pulleys are high performance and high quality products that Tsubaki has invested the utmost of its know-how into as a comprehensive power transmission manufacturer. Simple Machines – Levers and Pulleys A machine is something which helps us do work, that is, transfer energy. Or the pulleys at the front of your car engine which drive the water pump. • The children will understand how a basic pulley works. The unit of force is the Newton (N), and a force of 1 N is defined as the force that when applied to an object with a mass of 1 kg, produces an acceleration of 1 m/s 2. steam shovel. LESSON SEVEN Inventions BIG IDEAS An invention is a combination of simple machines, for example, a foot-pedal sewing machine or a car. A hands-on approach introduces young scientists to pulleys. How to present a project and impress your audience: Top 6 tips; 27 June 2019. For an example, the average sailboat may have 3 or 4 different pulley systems (boomvang, cunningham, outhaul, mainsheet), all doing different things. If you have shoulder pain or have had shoulder surgery, then physical therapy may be an excellent option to help you decrease your pain and improve your overall function. Simple machines are devices that can make a tough job easier by enabling a person to apply less force or to apply force in a direction that is easier to manipulate. There are six types of simple machines: lever, pulley, inclined plane, wedge, screw, and wheel and axle. marine pulley. Get the best deal for Collectible Pulleys, Blocks & Tackles from the largest online selection at eBay. PULLEY 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 along its circumference. 2-Day Shipping. n - number of ropes between the sets of pulleys. A weight with the mass of 0. The drive element of a pulley system can be a rope, cable, belt, or chain that runs over the pulley inside the groove. The example I provided earlier is likely the most common mechanism for injury. A Luff tackle, shown separated. And the first simple machine was invented. Cognitive scientists (scientists who study how people learn) have shown that physics students come into physics class with a set of beliefs that they are unwilling (or not easily willing) to discard despite evidence to the contrary. We'll also learn how to use Fan Law One to calculate how to change the dimensions of. So thank you Inclined Planes. n - number of ropes between the sets of pulleys. Third class: The effort happens between the load and the fulcrum. pul·leys 1. More loops and pulleys increases the mechanical advantage. This example models a pulley mechanism that takes a torque applied to a winch and transmits it to a pulley rotated at 90 degrees to that winch. Neglect the friction and the mass of the pulley and the string. Speed of Last Driven Pulley. A pulley consists of a grooved wheel that turns on an axle with a rope or cable riding in the groove 2. The belt runs from the drive pulley to a driven pulley. A double pulley system, also known as a "block and tackle," consists of the pulleys, or blocks, and the tackle, the. In both examples, the pulley system used is a cable system that makes lifting or moving the items attached to it easier. An extensible string passes over the groove where its one end is attached to the body to be lifted while the other end is free. The pulley is a type of ramp that minimizes rope friction, allowing the rope to transmit energy from a pull in one direction to movement in a different direction. Try also checking the widest part of your belt. Pulley lesions were created and studied at flexion, extension, and forced flexion. Find Cobalt SS Supercharger Pulley listings at the best value Cobalt SS Supercharger Pulley Used Cars - ZeMotor. A compound pulley is a system of movable pulleys. Simple Machines - Practice Problems Name _____ A crate of bananas weighing 3000 N is shipped from South America to New York, where it is unloaded by a dock worker who lifts the crate by puling with a force of 200 N on the rope of a pulley. It's another great storage option that you may not have thought of! With a few readily available tools, you can set up a garage pulley system from the ceiling in a few short hours. I purchased the California Umbrella 9' Wood Pulley Open Market Umbrella from Eastgate Dining Chair (Set Of 2) by DarHome Co with All Bar Stools in March 2015 and it broke in Mid-April 2015. The applied effort through pulling of the string rotates the pulley and pulls the load upwards, helping the load to be lifted with ease. One pulley enables you to change the direction in which a force acts. If you can work through and understand them you should be able to solve most standard pulley problems. Basically, all that a pulley is is a wheel spinning around an axle to aid the motion of a belt. ) Exercises 1. In this chapter, I guide you through the wonderful world of inclined planes, providing you. Motor pulley diameter(d S) = 300 mm, Pump pulley diameter(d L) = 600 mm Coefficient of friction (μ S) for motor pulley = 0. How to make a pulley using everyday materials: You will need - cardboard, scissors, glue, string, wooden skewer, a plastic bottle and bottle cap. com/products/images/medium. We still use these simple machines today, and we have learned to combine them to make complex machines. With these mechanical advantage system, you can generate a serious mechanical advantage in your favor, multiplying the force the user puts into the system. For example, if we have two pulleys attached to the rafter, two pulleys attached to the weight, one end attached to the rafter, and someone standing on the rafter pulling the rope, we have a mechanical advantage of four. We can neglect the mass of the pulley. by Ron Kurtus (revised 13 May 2019) There are three types or classes of levers, according to where the load and effort are located with respect to the fulcrum. Pulley Diameter in Compound Drive. steam shovel. A simple system that has revolutionized the way the human world works is the pulley system. Some pulley systems make work easier, allowing a worker to use less force to move the object. Learn about pulleys with this interactive video lesson on pulleys, for kids. The drive is transferred to another pulley using a vee belt (both pulley and vee belt are shown in the image above). In a double pulley, as the rope passes over the pulley the force is transmitted entirely but the direction has changed. Explanation about the Three Lever Classes. Simple motor pulley used in a sewing machine. ) Both Pulley A & Pulley B will require the same effort (force) D. This information is used to by DataStudio to compute the acceleration of the the system of masses. We can neglect the mass of the pulley. His version of the pulley objects of weights to heavy for any other systems before Archimedes’ compound pulleys system. Edelman Engineering is considering including two pieces of equipment, a truck and an overhead pulley system, in this year's capital budget. Generally levers are designed to magnify the forces applied to them. For more details view the video. Pulleys are used for exercise, especially in hospitals, to help patients grow stronger. A single rope is passed over these pulleys. oil derrick. A pulley is a basic device or machine made of a wheel with a rim that a cord or rope fits around. Loading a carabiner in any other way can be dangerous. LESSON SEVEN Inventions BIG IDEAS An invention is a combination of simple machines, for example, a foot-pedal sewing machine or a car. The wheel is usually grooved for a rope or a wire cable. Pulleys provide high motive strengths applied to the load, and enable control of the movement of the object. Engineers in the Aerospace, Automotive, Medical, Off-Highway and Oil & Gas industries are just a few of those who have specified Smalley Rings. So thank you Inclined Planes. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician. Pulley definition is - a sheave or small wheel with a grooved rim and with or without the block in which it runs used singly with a rope or chain to change the direction and point of application of a pulling force and in various combinations to increase the applied force especially for lifting weights. This is also known as the block and tackle pulley system which utilizes the mechanical advantage of lifting a weight with only half the force to lift it. A hockey stick is an example of what simple machine? A Class 1 lever B Class 2 lever. ) Pulley A B. Block Division's block and tackle pulley system products, including fixed eye, swivel eye, fixed hook, swivel hook, bolt, strap, and deck blocks, with single, double or triple sheaves, as well as replacement sheaves, bushings and bearings, can be used in various different businesses and field use (such as hunting), as well as for personal use or just for fun. Driver 4mm Follower 1mm Compound Drive Pulley Trains A Compound Drive Pulley Train has pairs of pulleys working in combination, with the follower of one pulley sharing the same axle as the driver of the next sequential pulley train. ) Not enough information to decide. DEPENDENT MOTION EXAMPLE Consider a more complicated example. This example has been based upon the idea of masses sitting on the lever, but the mass could be replaced by anything that exerts a physical force upon the lever, including a human arm pushing on it. Speed of Last Driven Pulley. Its job is to change the direction of pull on the rope. These SPA Pulleys will run with a SPA V Belt. Grade 8 – Unit 4 Test _____ _____ Student Class 1. Some examples of pulleys are cranes and flagpoles. Examples of Pulleys: Pulleys are used to open and close curtains and blinds. 4-A TUHD Bearing Bolt Pattern Example. By looping more ropes around more pulleys we can construct a block and tackle to continue to increase the mechanical advantage. A What is a simple machine? A simple machine has got few or no moving parts. This science lesson is appropriate for students in 2nd, 3rd, 4th, 5th, and 6th grades. We stock a wide variety of winches and pulleys used for lifting and transporting applications. • Vee belt. These kinds of pulleys are often used in cars. It uses the principle of applying force over a longer distance, and also the tension in the rope or cable, to reduce the magnitude of the necessary force. For example, cars, bicycles, most luggage, and doorknobs use wheel and axels. BY STEVE DINAN OF DINAN BMW. Both cranes and flagpoles have a pulley at the top of their poles. Example: System with Pulley (Solution 2: effective elements) Repeat the previous example using effective elements. 144 Inch to 0. We then examined and dissected proximally the palmar pulley which was incised with the tenotomy scissors. In this lesson students learn about one of the six simple machines called a pulley. Pulleys of medium or large-diameter (Figure l,b) have a hub (1) and a rim (2) connected by a web (3) or by arms. Pulley – A pulley uses grooved wheels and ropes/chains to raise, lower, or move a load. When the engine is operating, the crank pulley rotates, transferring motion to the other pulleys by means of the serpentine belt or v belt. A compound pulley is a system of movable pulleys. The wheel is fixed in one spot and the rope moves through the groove in the wheel as shown in the image below. They review real-world examples of pulleys and practice identifying the characteristics. How to Replace and Install a rear Wheel Bearing BMW e46 Home tools Diy Step by Step replace and Install a new rear wheel bearing Bmw e46, e39 Tutorial pas cu pas demontare si instalare rulment roata spate Bmw e46, e. The rod moves through this hole as it is turned. If you like playing with objects, or like drawing, then geometry is for you! Geometry can be divided into: Plane Geometry is about flat shapes like lines, circles and triangles shapes that can be drawn on a piece of paper. Then the weight hanger ( P ) was attached at the free end of the nylon rope. Lever – A lever is a bar that rests on a support and can be used to lift or move loads. Volleyball Net Demo/ Flagpole 3. 4-A TUHD Bearing Bolt Pattern Example. Pulleys: Applications and Uses. They make lifting easier by changing a push upward to a pull downward. Attach pulley securely over the top of the door. A see-saw is an example of a class-1 lever. A wheel & axle is a special kind of lever, where the center of the wheel is the fulcrum. Specify own resultant load R for each pulley with the help of belt tensions and general calculation methods. The tension in each line is half the unit weight and there is an advantage of 2. Pulleys can be multiplied in any number of ways to accomplish a variety of tasks. 50 kN Attention! A rope with a too small diameter may fit between the pulley and the side plate. Description Solution of a problem to calculate tension acceleration of a block, pulley system by drawing a free body diagram--the most common type of example which the students of competitive exams. Pulley – Old wood windows, some garage doors, workshop or garage lifting systems. 3 July 2019. examples of machines that have pulleys: Block and Tackle Car Engine Sewing Machine Air compressors Scooters http://www. Pulleys & Pulley Systems for Rope Rescue & Climbing. Masses m 1 and m 2 are connected by a string which runs over a pulley and mass m 2 sits on a smooth inclined plane. How to present a project and impress your audience: Top 6 tips; 27 June 2019. 1 Class One - Welded Hub 3. The same amount of work is done, but it is done more easily, and less force may be required. Performance Assessment: In each example of a simple machine, the children should be able to explain how the machine helped to reduce effort, increase force, or change the direction of force. Antique Pulleys. In both the drives, a belt is wrapped around the pulleys. There are after all easier ways to do everything and science has empowered us. Examples would be a a simple saw bench where pulleys are on the motor spindle, and another on the saw shaft. The belt runs from the drive pulley to a driven pulley. The short string needs to be pulled many more times. Hanging chandelier, which can be lowered. Tip: I removed the seized pulley, disassembled it, found that several ball bearings were missing and those that left weren't in good shape. If you can work through and understand them you should be able to solve most standard pulley problems. Mechanical Aptitude Test - Pulleys A pulley is defined as "A wheel with a grooved rim around which a cord passes. As with gears, the velocities of pulleys are inversely proportional to their diameters. 5 kg and the pulley has a mass of 1. Both cranes and flagpoles have a pulley at the top of their poles. But wedges can also hold things together as in the case of a staple, push pins, tack, nail, doorstop, or a shim. Also, h is a constant. • The children will be able to carry out simple calculations to measure the mechanical advantage of different pulleys. Q1) If we ignore friction, which of the following two pulleys systems will require less effort (force) to lift the load? A. Pulley systems are used to provide us with a mechanical advantage, where the amount of input effort is multiplied to exert greater forces on a load. Changing Direction: You can change direction in a pulley system by looping the belt in a figure eight between the pulleys. If there is friction between the string and the pulley, so that the string does not slide around the pulley but the pulley rotates, there should be no friction between the pulley and the axle/pivot. Lesson learned: I now carry a spare pulley wheel. A pulley consists of a grooved wheel and a rope threaded around the disk. There is often another matching piece with a hole threaded on the inside. Instead, it only changes the direction of the force, as with a Venetian blind (up or down). 2 – Connectors. A weight with the mass of 0. Lighten the Load with a Pulley. Timing Pulley Terminology Timing Pulleys Timing pulleys have evenly spaced axial grooves cut in their periphery to make correct, positive engagement with the mating teeth of the belt. The last type of simple machine is the pulley. Example of Pulley System. ) Pulley A B. For this pulley system, only the first picture shows the entire system, but due to its size, it is not clear. Examples of Pulleys in Everyday Life Elevators. Three Lever Classes. This science lesson is appropriate for students in 2nd, 3rd, 4th, 5th, and 6th grades. What do you understand? What is still confusing? Meet with your group to discuss materials for the classroom machine building contest. Neglect the friction and the mass of the pulley and the string. Stock pitches include. Multiple Pulley's Lifting Mechanical Advantage Mechanics and Machines Calculations Menu The following are the equations and calculator to determine the lifting forcing and velocity ratio of a differential pulley. If the middle pulley on the countershaft is made to drive the identically-sized pulley on the lathe spindle that too, of course, will turn at 300 r. For the groove depth, enter the belt’s thickness. In open belt drive system the rotation of both the pulleys is in. Setting up a simple platform pulley system is one way to solve this and other garage issues, allowing you to conveniently access storage within the rafters. Examples of Pulleys. 0; This page has been so popular that I decided to package the form into a desktop application. Fixed Pulley; When the block of the pulley is fixed on a high platform, it is known as Fixed. The pulleys and or the idlers are out of square with the belt centreline. Antique Pulleys. How to Make a Pulley - An Easy Science Activity for Kids When I came across the book Explore Simple Machines! , I had to pick it up. Unless you have specific. Harbor Freight buys their top quality tools from the same factories that supply our competitors. Examples would be a a simple saw bench where pulleys are on the motor spindle, and another on the saw shaft. 4-A TUHD Bearing Bolt Pattern Example. A movable pulley is a pulley that is free to move up and down, and is attached to a ceiling or other object by two lengths of the same rope. Examples of Different Types of Pulley Systems. Single Belt Transmission - one driving pulley and one driven pulley. Instead, it only changes the direction of the force, as with a Venetian blind (up or down). Fixed Pulley; When the block of the pulley is fixed on a high platform, it is known as Fixed. Further examples of forces are discussed later in this text. Shoulder pulleys are an excellent way to improve rotator cuff and shoulder range of motion after injury or surgery. Note: These two examples show calculations for a weight and pulley window system. Tail pulleys can utilize internal bearings or can be mounted in external bearings and are typically located at the end of the conveyor bed. It's easier to pull than to lift. V Pulley - SPA. Simple Machine Questions for Simply the Best. A pulley is one of the six simple machines that human beings use to help them lift and move objects. The advantage of a simple pulley is that it allows you to change the direction of the force required to lift it. An example of Atwood's machine (masses on a pulley) Also, the mass of the pulley must be small (technically the moment of inertia of the pulley must be small). When multiple pulleys are used together it's called a block and tackle. Examples of sexual harassment. A movable pulley acts as a second -class lever, the load (resistance) is between the fulcrum and the effort. One end of the rope is tied to the load, while the other end is fitted into the wheel. Many bottles and jars have screw on lids. 80kg and a block of mass m 2 = 6. The applied effort through pulling of the string rotates the pulley and pulls the load upwards, helping the load to be lifted with ease. We call these screws bolts. These can include reciprocating, rotating, and transverse moving parts, as well as feed mechanisms and auxiliary parts of the machine. View American English definition of pulley. For this pulley system, only the first picture shows the entire system, but due to its size, it is not clear. You will need some wire, thread, a spool, a hook and a bucket filled with toys or other materials. The mechanical advantage can be increased by using a block and tackle, where there are several pulleys on each axle. ★ Deal Shop Chairs Recliners Sale ★ Sharyn Upholstered Dining Chair by Brayden Studio Huge Selection And Special Prices For You Home. Step 2: Position coordinates. 25 Coefficient of friction (μ L) for pump pulley = 0. In both examples, the pulley system used is a cable system that makes lifting or moving the items attached to it easier. Grade 8 – Unit 4 Test _____ _____ Student Class 1. Examples would be a a simple saw bench where pulleys are on the motor spindle, and another on the saw shaft. A fixed pulley is a pulley that is attached to a structure, it can not move relative to the structure. If you know any 3 values (Pulley sizes or RPM) and need to calculate the 4th, enter the 3 known values and hit Calculate to find the missing value. • The children will be able to carry out simple calculations to measure the mechanical advantage of different pulleys. Attention! Always insert the connector. Another example is a bottle opener where the fulcrum tucks under the edge of the lid, and one end of the bar rests on the lid. " These two types can be combined to create a more complex pulley system. The higher the mechanical advantage, the easier it is to lift a weight. CLICK HERE FOR NEXT PULLEYS AND LIFTING PAGE. A movable pulley consists of a shell, a movable wheel and a rope. b) Find the magnitude of the tension of the string between m 1 and m2. This topic provides examples of both. When working through pulley problems in Engineering Dynamics, we will usually make the following assumptions. It’s purpose is to either change the direction of force or to change the magnitude of the force 3. They are the fixed pulley, moveable pulley and pulley system. One example is kitchen tongs , where the hinge is the fulcrum, the input force comes from the user’s hands, and the output force is exerted at the tip of the tongs. Belt and Chain Drives (Flexible Drive Elements) Type Pulley 1. Once you have selected your answer be sure to have a look below to learn how they are properly solved. Common examples of pulleys are found in window blinds, curtains and flagpoles. The stresses in a pulley connected to an engine that drives another pulley are studied in this model. Browse a variety of top brands in Rope + Pulley Hoists such as Jet, Ingersoll Rand, and Grip from the product experts. A pulley is a simple machine consisting of a string (or rope) wrapped around a wheel (sometimes with a groove) with one end of the string attached to an object and the other end attached to a person or a motor. List the sources in alphabetical order using the author's last name. To find the total ratio, use the pulley ratio formula: Ratio = (Radius of Driven Pulley) / (Radius of Drive Pulley) Example: A handcrank is attached to a drive pulley of 2 inches in radius. A pulley is a grooved wheel with a rope around it. Using two or more pulleys reduces the amount of effort needed. Example 3: A block of mass m 1 = 1. As the load is being supported by two sections of rope (via pulley A), each rope will bear half of the loads weight or 50kg in this example. The Usual Pulley Assumptions. Define pulley. During operation, this. By looping more ropes around more pulleys we can construct a block and tackle to continue to increase the mechanical advantage. How to use Prezi Analytics to learn from your presentations. A pulley is one of the six simple machines that human beings use to help them lift and move objects. How to Calculate MA of Simple Machine of Pulleys The effort needed to lift a load can be halved by using two pulleys: one fixed and the other moving. 5 kg and the pulley has a mass of 1. Pulleys with grooved rims are called sheaves.