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Why is it easy 2 lift a load using pulley than lift it directly?
Wiki User
∙ 16y ago
When you lift an object, three things happen:
1) The lower extremities take on the weight of both your body and the object being lifted, and..
2) Your center of gravity is offset in front since you must lift the object in front of your body. This forces you to compensate using a change in posture, making more muscles work to lift. (Think of how long you can stand straight, verses how long you can stay in a stooped position.)
3) Since your hands are extended, this essentially uses your hands as a lever against you. (Take a weight, and lift it close to your body and compare it with lifting it with your arm straight out.. you will feel the difference!)
For instance, if I lift a large box, I need to extend my hands at least to the center of the box. My arms are acting as a lever, and my center of balance is moved forward. This places added strain on my body. My legs have also taken on the extra weight of the box.
Pulleys essentially redirect force along the path of the rope. This allows the force to be placed in a way that is easiest for our bodies to apply.
If I use a pulley, my legs are actually under less strain. Also, since I can pull the rope close to my body, the weight is not levered against me, and my center of gravity is only altered minimally. I can then use my body in its most efficient manner to exert the force required to lift the box.
Wiki User
∙ 16y ago
Wiki User
∙ 12y agoThe use of a block and tackle provides a mechanical advantage so that you have to pull more rope, but you don't have to pull it as hard as you would otherwise.
For example, using a block and tackle with an MA of 2 to lift a load of 100 kg 10 meters means that you have to pull 20 meters of rope, but you only have to pull it with a force of about 499 N instead of the full 998 N you'd have to use to actually lift the load directly. A complex block and tackle system can increase the MA even more, allowing you to use progressively less force at the cost of having to shift the rope more.
Wiki User
∙ 14y agoThe pulley is for moving heavy things around. Archimedes used his invention to pull a fully-loaded ship.
Wiki User
∙ 14y agoThat is because a pulley is specifically designed to reduce the force required. In compensation, you need to pull for a larger distance. This is related to conservation of energy.
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Will the force applied to lift a brick reduce if you use pulleys?
yes, pulley will help IF not the if YOU USE COMBINE TWO OR MORE PULLEYS. Yes, using a pulley or a system of pulleys will reduce the force needed to lift a brick (or anything). HOWEVER the distance that the rope (or whatever effects the pulley system) has to now travel further so that the energy required to lift the brick through an equal height is always the same.
More information of uses of pulley?
Pulley systems are used in the real world to lift large masses onto tall heights. You might have seen the workers repairing the roof of a house and using the pulley system to lift their tools or materials to the roof. A pulley is an example of a simple machine.The pulley system consists of one or more pulleys and a rope or a cable. The number of pulleys used may increase or decrease the mechanical advantage of the system. Generally, the higher the mechanical advantage is, the easier it is to lift the object that is being lifted.Overall, no matter how easy it is to use the pulley system, the system itself is not very efficient due to the force of friction. For example, one has to pull two meters of rope of cable through the pulleys in order to lift an object one meter.The applet below illustrates just that. Select the number of pulleys and drag the mouse to see the inefficiency of the system.
How do lifts and elevators work?
The cabin of the lift is raised (and lowered) by a pulley. The pulley has a counterweight, which weighs as much as an empty cabin. Therefore, the wheel at the top of pulley does not need to lift the entire weight of the cabin - just the extra load in the cabin.
When would you use a one system pulley?
I think you mean "a one pulley system." When you want to pull in the opposite direction you want the object to move. If you tow a log behind a vehicle you don't use one so the log follows the car. But, if you wanted to lift that log you would throw the rope over a tree branch or pulley to lift it into the air as you pull down, thus using your weight with gravity to help lift the log.However, by attaching the pulley to the tree branch, you don't gain any mechanical advantage other than using gravity with pulling down.If, on the other hand, you attach your one pulley to the log, attach one end of the rope to the tree branch, and lift up with the other end you do gain mechanical advantage with it requiring half the force of the previous example of pulling down. But, you are limited by working against gravity and you can only lift as high as you are standing.
A fixed single pulley that is used to lift a block does what?
The choices are:A. Doubles the force required to lift the blockB. Decreases the force required to lift the blockC. Makes the block easier to lift by changing the direction of the force needed to lift it.D. Decreases the force required and changes the direction of the force required
What is one example of a combined pulley?
make life easy to lift
Does the force used to lift an object using a single pulley alter depending on the size of the pulley?
no
What is making it easier to lift the load?
The mechanical advantage of the block and pulley you are using, or the engine of the fork lift truck if that is what you are using.
When using a pulley to lift box what force are you trying to overcome?
Gravity
What is the definition of a rope and pulley?
A device used to lift something heavy. By using a pulley, you half the effective weight.
When you lift very heavy weights what pulley system are you using?
Single Moveable
What pulley system will lift the weight using the least amount of effort force?
balls. =))
What do we use a fixed pulley for?
this is berat writing.we use fixed pulley for lifting load up only by using force on the effort that makes the load lift
How much effort will be needed to lift 10 newtons using a singal fixed pulley?
10 N
What are some example sentences for 'pulley'?
A pulley is used to move a heavy weight. You can use a pulley to lift something that you can't lift alone.
What is important about a pulley?
Pulleys make lifting things easier. example: If you want to lift 100kg you don't want to lift it with your hands, so you use a pulley. The best choice would be to use a pulley with 4 wheels. Using this would make the effort to lift the 100kg about 75% easier. So lifting the 100 kg with a pulley would make the object be about 25 kg. That is why pulleys are important.
Is pulley defined as an adverb?
Pulley is a noun, as in "the pulley helped lift those pallets over there".
