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How do you calculate the mechanical advantage of a pulley system?
Wiki User
∙ 11y ago
The mechanical advantage is the ratio of the distance your hand moves to the distance the piston travels. For instance, if the lever is 21" long and a full rotation of the level produces a piston travel of 7" then your hand would move 2*pi*21" (131.9"). The ratio 131.9:7 reduces to 18.8:1. If you wanted to produce 1 ton (2000 lbs) of force on the piston you have to appy 106 lbs on the 21" lever.
Wiki User
∙ 10y ago
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Which is equal to the ideal mechanical advantage of a pulley system?
It only takes half the effort to move an object but twice the distance
How can the mechanical advantage of a pulley system be determined without using any equations?
by seeing how many ropes the pulley has... that is close to the mechannical advantage...or it is it! its a cool trick once you learn it! My science teacher just had us do a project on this!
What would happen to a pulley system if the load were increased?
Ideal mechanical advantage is the mechanical advantage when there is no friction. It is the mechanical advantage when the efficiency of the pullefy system is 100%. It is a constant for that system of pulleys. Therfore it is not affected by increasing or decreasing the load. But actual mechanical advantage will be less than this ideal mechanical advantage due to friction. In other words the efficiency will be less than 100 %. If the efficiency is 80%, it implies 20% is wasted due to friction while lifting a load. If we increase the load the friction also increases and hence the efficiency will decrease with the load.
What pulley system creates just directional advantage?
Single fixed pulley
How do you calculate the ideal mechanical advantage of a pulley system?
A pulley system creates mechanical advantage by dividing force over a length of rope or its equivalent, that is greater in length than the maximum distance the load can travel by using the pulley system. Through the use of movable pulleys or their equivalent, a system creates a mechanical advantage through the even division of force over multiple rope strands of a continuous rope. As rope, or its equivalent, is removed from the system, pulleys, or their equivalent, allow the side of the rope to apply force to the load. As the the system contracts, the load is lifted or moved (depending on the direction of the pull). The more strands created by the configuration, the greater the mechanical advantage. This is because every strand of rope or its equivalent created by the configuration of the system will take an equal amount of length of rope removed as the system contracts. Thus if there are three strands of rope created by the system, and three units of rope are removed from the system, each strand will contract by one unit. As the strands are parallel, or function in as parallel the overall contraction of the system is one unit, moving the load only one unit for every three units of rope removed. By distributing the force needed to move the load one unit over three units of the rope, this decreases the force needed on the pulling end by 1/3. This would be a mechanical advantage of 3:1. One of the most common systems of mechanical advantage is a shoe lace system. The grommets of the system are the equivalent of movable pulleys. As lace is removed from the system, force is applied to grommet, contracting the system. The laces are much longer than the space that they are contracting, and to fully contract the space nearly all the lace must be removed, so we can clearly see that many more units of lace must be removed for every one unit of contraction in the system, thus mechanical advantage is created. Of course in a lace system friction quickly overcomes and limits the advantage created. But on the other hand the friction helps to hold the force exerted allowing you to cinch up you shoes more easily. Now with this example in mind, let's look at a more traditional pulley system. The easiest way to understand how mechanical advantage is achieved may be to focus on the geometry of the system. Specifically by focusing on how force is applied to the load and why the configuration of movable pulleys distributes force and creates mechanical advantage. Imagine a weight to which a rope is directly attached. The rope is fed though a pulley mounted on the ceiling (fixed pulley). If you were to pull the rope the weight would move up a distance equal to the length of rope pulled. This is because the rope is directly attached to the load. There is no mechanical advantage. If we want to create a mechanical advantage we must attach a pulley to the load/weight so that force is applied via the rope's contact with the movable pulley . So in the next scenario imagine the rope is directly attached to the ceiling, and is fed through a pulley attached to the load (movable pulley as the load can move). The distance from the movable pulley to the ceiling is 10 feet. Now imagine you were to grab the rope exiting the pulley (imagine the system has no slack), and raise it to the ceiling. Now you have 10 foot section of rope with both ends on the ceiling. Where does that leave the load? Since the load is connected to the system by a wheel that can travel over the rope it has not followed the end of the rope the 10 feet to the ceiling, instead it has stayed in the center of the rope, constantly dividing the distance of the remaining section of rope. The load will now be 5 feet from the ceiling (10 feet / 2 section of rope). It has move only 1 unit of distance for every 2 units the rope has moved. Therefore only 1/2 the force is needed to move the rope 1 unit. This movable pulley system therefore has a 2:1 mechanical advantage. Now we will add another pulley to the ceiling. This is a fixed pulley and will not add any mechanical advantage, but will only redirect the force applied to the system. If we add another pulley to the load we will then have added mechanical advantage. When calculating the advantage added, you must observe the movable pulleys and their relationship to the load. Imagine a system with a rope directly connected to a load. The rope travels through a fixed pulley on the ceiling to another pulley on the load and back up to a fixed pulley on the ceiling. Drawn on paper this system will have four rope strands. For calculating mechanical advantage you must not count the strand exiting the final fixed pulley as the fixed pulley does not add mechanical advantage. (if the system was to end with a pulley attached to the load you would want to count the final strand). In this scenario we have three strands of rope contributing to the mechanical advantage of the system so the advantage should be 3:1. But how can you prove this. Imagine each section is ten feet long. Thus we have 30 total feel in the system. We pull out 10 feet of rope, how far has the load traveled? Well, we know we now have 20 feet of rope in the system distributed over 3 equal strands of rope. That would make each strand approximately 6.66 feet long. The load would therefore be approximately 6.66 feet from the ceiling or 3.33 feet from the ground (10 - 6.66). By traveling only 3.33 feet for 10 feet of rope removed from the system we have 3:1 mechanical advantage ratio (10:3.33). A final thought exercise to intuitively understand what can be a very unintuitive process. Imagine a 10 ft tall pulley system. Now focus on the amount of rope in the system. If you have three strands going back and forth you will have 20 to 30 feet of rope in the system (depending on if the final pulley is attached to the load or a fixed point). If you have four strand you'll have 30 to 40 feet. The particular amount is not important. What is important is to see that the only way the load can travel the 10 feet to the top of the pulley system is for nearly all the rope in the system to be removed be it 20, 30, 40, 50... ect. The more rope that must be remove/the more strands that divide the amount removed, the greater the division of the force over the rope and the less force is required on the pulling end of the system. Of course this is a basic pulley system. If you attach pulley systems to pulley systems (piggy back systems) you can begin doubling forces quickly, and strands need not be equal in length for their dividing power to function. Z rigs, trucker's hitches, and others create mechanical force through attaching or creating a movable pulley to/on the rope. The overall geometry of the systems and the relationships of elements stay the same as does the reason for the mechanical advantage. It is also important to note that there are configurations where a pulley or its equivalent may not be "movable", but mechanical advantage is created. Imagine multiple pulleys fixed to a ceiling and floor of a room. If one end of a cable was fixed to either the floor, ceiling or one of the pulleys and the system was threaded, it certainly would be creating a mechanical advantage. Though all pulleys are technically "fixed" the opposition force is magnified just as in any other system, and depending on the strength of the cable, ceiling, or anchors, one element may eventually fail because of the tension in the system. The amount of tension in the system is created though the mechanical advantage of the configuration, and though nothing may move but the cable, magnified force is applied to the elements of the system. In summary, it may be helpful to focus on the geometric relationships in pulley systems to better and more intuitively understand the way in which they create mechanical advantage.
What is the mechanical advantage of the pulley system?
The mechanical advantage of the pulley system is the inertia and friction of the unbalanced and balanced forces acting on the mechanical advantage which is part of the pulley system....
What is the mechanical advantage of systems of pulleys?
The mechanical advantage of the pulley system is the inertia and friction of the unbalanced and balanced forces acting on the mechanical advantage which is part of the pulley system....
What is equal to the ideal mechanical advantage of a pulley system?
The ideal mechanical advantage of a pulley system is two times the number of pulleys in the system. This is the amount of force required to get the system moving.
What is the advantage of adding pulleys to a pulley system?
More mechanical advantage.
Can a pulley system provide both a directional advantage and mechanical advantage at the same time?
yes
How does the different type of pulley system affect the mechanical advantage?
Depending on the type of pulley system you have (Fixed/ movable/ combined pulley) using either of these will give you mechanical advantage. The different pulley types are designed to even the weight of the object your pulled out, this will enable you to lift heavier objects with a lighter pull
Which is equal to the ideal mechanical advantage of a pulley system?
It only takes half the effort to move an object but twice the distance
a pulley system uses a 250-N force to lift a 2,740-N crate, What is the mechanical advantage of the system?
Answer: Mechanical advantage can be achieved just by adding more loops or pulleys. It is given that to lift a crate, a pulley system exerts a force of 2,740 newtons. It is required to find the mechanical advantage of the pulley system if the input force is 250 newtons What is the mechanical advantage of the pulley system if the exerted force changes from 2,740 newtons to 250 newtons? As if the force does some work, it increases the distance. Mechanical advantage does nothing with the number of pulleys. It only depends on the weight that is to be lift. Also, F1/F2 = 2740/250 = 10.96 The multiple pulleys create mechanical advantage. It can be achieved just by adding more loops or pulleys. Therefore, Mechanical advantage can be achieved just by adding more loops or pulleys.
What is the advantage of a pulley?
Of a single pulley wheel, only that it changes the direction of the force ie: from overhead. > On a block and tackle system, 2 or more pulley wheels are used in a certain way to produce mechanical advantage. The simplest type of block and tackle offers a mechanical advantage of 2
What is the mechanical advantage of a combined pulley?
A ratio that is the number of falls of rope in the system, apart from the rope between head-pulley and winch or you.
Which is better a incline plane or pulley?
A single pulley simply changes the direction of the force. A block and tackle or multiple pulleys can offer a mechanical advantage - same as an inclined plane. For the same mechanical advantage, a pulley system may be better because of lower friction.
A pulley system is used to lift a 2000 newton engine up a distance of 3 meters How much force will the operator have to apply if the mechanical advantage of the pulley system is 4?
A pulley system is used to lift a 2,000 newton engine up a distance of 3 meters. How much force will the operator have to apply if the mechanical advantage of the pulley system is 4? mechanical advantage = 500 newtons.
