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How do you calculate the mechanical advantage of block and tackle?
Wiki User
∙ 13y ago
Let's look at a simple system. A block with three wheels is attached to the ceiling and a block with three wheels is attached to a load to be lifted off the floor. As well as the block attached to the ceiling, we have a hook there also near to the block and we start by knotting one end of our rope onto that hook.
We now run the free end of the rope through the bottom block, back up through the top block, back down to the bottom block and so on, finishing up with the free end of the rope coming out of the third wheel at the top and hanging down.
Now for the physics. Physics says that a well oiled pulley wheel cannot alter the load in a rope passing over it. Therefore, we have to accept that the load in any part of the rope is the same. Now we count how many lengths of rope are going to be lifting the load. I see six. Three wheels in the bottom block and two lengths of rope to each wheel. As these six ropes are all pulling upwards when we pull down on the free end, and the load in each rope is the same, the load in the rope is one sixth of the weight to be lifted. This is the pull required on the free end just to hold the load off the floor. A sightly greater pull will overcome any friction in the pulleys and start the load moving upwards.
The mechanical advantage of the system we have here is 6.
An interesting variation is when we have four wheels in the bottom block and pass what was the free end hanging down through the fourth wheel. We now have the free end to be pulled upwards and it will be contributing to the lifting forces on the weight. There are now eight lengths of rope lifting the weight and the pull required will be just a tad more than one eighth (1/8) of the weight to be lifted.
Wiki User
∙ 13y ago
Wiki User
∙ 11y agoNo, the costume that you wear has no effect on the mechanical advantage.
The word is "ropes" and the answer is "yes", it equals the number of ropes carrying the weight. Easily proved by working out the tension in the rope.
Wiki User
∙ 12y agoMA = Distance moved by input (you) / distance moved by load
Input force * MA = output force (friction losses ignored)
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What does it mean to have an ideal mechanical advantage of 7?
The ideal mechanical advantage is calculated as: Ideal_Mechanical_Advantage = distance_moved_by_effort / distance_moved_by_load. It is ideal because it ignores real world factors like energy lost through friction. So an Ideal Mechanical Advantage (IMA) of 7 means that the machinery amplifies the applied effort by 7. For example, a 7 kg load can be balanced using a block-and-tackle arrangement (which has 7 ropes supporting the load block and thus an IMA of 7) using only 1 kg and lifted by applying slightly more than 1 kg. In the real world, there is friction between the pulleys and their bearings so that more real effort is required before the load moves and the real Mechanical Advantage of the above block-and-tackle arrangement is less than 7.
How many parts to a block and tackle before you lose mechanical advantage?
The answer depends on the quality of the components used. It also depends on whether you use a simple system with just 2 blocks, or use a cascaded system where the output of one block and tackle feeds the input to another. The only other answer I can give is "it's fewer than you think".
What does double pulley system mean in science?
A "double pulley" may refer to a two-block (two rope) pulley, or to the arrangement of two separate pulley blocks as a "block and tackle" -- designed to make lifting easier by reducing the necessary lifting force: a smaller force is applied over a greater distance to achieve a mechanical advantage.
How do you find the mechanical advantage of a simple machine?
To find the mechanical advantage of a simple machine divide output force by input force. (input force is the force that we exert on a machine, and output force is the force that is exerted by a machine).
Is a block and tackle a wheel and axle?
No, a block and tackle is not considered a wheel and axle system. It is considered a type of pulley system.
Mechanical advantage of the block and tackle?
Equal to the number of cords supporting the weight.
What is a block and tackle used for?
Block and tackle refers to a rope threaded through a series of pulleys to provide mechanical advantage, and it is used to lift heavy objects,
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
Is the mechanical advantage of a block and tackle equal to the number of ropes used to raise the object?
look in your ducking textbook
If a block and tackle is a simple machine What mechanical advantage does it give the user and what does the user have to give up in exchange?
The mechanical advantage is that the force applied increases but that is compensated by the fact that the rope or chain needs to be moved through a greater distance.
How is a block and tackle is used today?
The block and tackle is still used in the manner it has always been used, to gain a mechanical advantage in lifting or pulling objects. It is used extensively aboard ships today. I used them in the Navy. I have also used the block and tackle on construction jobs when rigging heavy loads to move them. The block and tackle is very handy when there is no source of electric power available and in remote locations.
How does a block and tackle work?
By mechanical advantage. The multiple lengths of rope divide the force needed to lift an object everytime the rope reverses direction thru a pully.
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.
What does it mean to have an ideal mechanical advantage of 7?
The ideal mechanical advantage is calculated as: Ideal_Mechanical_Advantage = distance_moved_by_effort / distance_moved_by_load. It is ideal because it ignores real world factors like energy lost through friction. So an Ideal Mechanical Advantage (IMA) of 7 means that the machinery amplifies the applied effort by 7. For example, a 7 kg load can be balanced using a block-and-tackle arrangement (which has 7 ropes supporting the load block and thus an IMA of 7) using only 1 kg and lifted by applying slightly more than 1 kg. In the real world, there is friction between the pulleys and their bearings so that more real effort is required before the load moves and the real Mechanical Advantage of the above block-and-tackle arrangement is less than 7.
What pulley is attached to the load and moves as the load moves Hi I'm Gretchen?
Hi Gretchen, this arrangement to gain mechanical advantage is often referred to as a "block and tackle". It consists of pulleys and ropes, usually not more than four, where the pulley attached to the load moves with the load, and the mechanical advantage is determined by the number of ropes.
How many parts to a block and tackle before you lose mechanical advantage?
The answer depends on the quality of the components used. It also depends on whether you use a simple system with just 2 blocks, or use a cascaded system where the output of one block and tackle feeds the input to another. The only other answer I can give is "it's fewer than you think".
Which machine has the greatest mechanical efficiency a block and tackle or a lever?
In theory there is no difference in efficiency (it would be 1), but in practice I think a block and tackle would lose more force to friction in the pulleys and between the rope and pulleys.
