How do you calculate the mechanical advantage of a compound pulley?

The mechanical advantage of a compound pulley equals the number of lines (e.g., ropes) that support all the movable pulleys in the system.

It almost seems magical that tremendous weights can be controlled by simply attaching a number of pulleys to them using a system or lines — like ropes or cables or wires — and pulling with a small amount for force. An arrangement like this is often called a “block and tackle” system.

Haven’t Found The Relevant Content? Hire a Subject Expert to Help You With
How do you calculate the mechanical advantage of a compound pulley?
Post Your Own Question And Get A Custom Answer
Hire Writer

The “block” refers to in the “block and tackle” refers to one or more pulleys, often called sheaves, mounted in a single assembly. Simple blocks may use one pulley, but for lifting very heavy weights many pulleys are often combined onto a single axle and mounted together with lines wound around them connecting the pulleys.

The whole assembly of several blocks and the lines that connect them is called the “tackle.”

To understand how a block and tackle (a.k.a., compound pulley) works, it’s only necessary to remember that the work required to move something is given by the force applied multiplied by the distance the object is moved.

If you just attach a line to an object and use a contstant force ##F## to move it a distance ##D##, the work is just ##F cdot D##.

If you loop the line around a single, fixed pulley (or sheave), all the pulley does is change the direction of motion so that the same, so that there is no real advantage and the work required to move the block a distance ##D## is the same: ##F cdot D##.

If, however, a moving sheave is attached to the object and the line is attached back to the fixed pulley, everything changes. Because the force is shared by the two lines attached to the moving sheave, the force exerted on the line held by the user is reduced by half. On the other hand, because the same total energy is required to move the object the full distance D, the lines must be pulled twice as far. This can be expressed mathmatically by noting that the total force ##F cdot D## (for a single fixed pulley, or no pulley) ##= F/2## (for the moving pulley with 2 lines attached attached) * ##2 D##.

This can be extended to multiple moving pulleys and lines: the force multiplier equals the number of lines attached to the moving pulley.

For more information on this, and other devices that provide mechanical advantage, check out the following link:

Calculate the price of your order

Select your paper details and see how much our professional writing services will cost.

We`ll send you the first draft for approval by at
Price: $36
  • Freebies
  • Format
  • Formatting (MLA, APA, Chicago, custom, etc.)
  • Title page & bibliography
  • 24/7 customer support
  • Amendments to your paper when they are needed
  • Chat with your writer
  • 275 word/double-spaced page
  • 12 point Arial/Times New Roman
  • Double, single, and custom spacing
  • We care about originality

    Our custom human-written papers from top essay writers are always free from plagiarism.

  • We protect your privacy

    Your data and payment info stay secured every time you get our help from an essay writer.

  • You control your money

    Your money is safe with us. If your plans change, you can get it sent back to your card.

How it works

  1. 1
    You give us the details
    Complete a brief order form to tell us what kind of paper you need.
  2. 2
    We find you a top writer
    One of the best experts in your discipline starts working on your essay.
  3. 3
    You get the paper done
    Enjoy writing that meets your demands and high academic standards!

Samples from our advanced writers

Check out some essay pieces from our best essay writers before your place an order. They will help you better understand what our service can do for you.

Get your own paper from top experts

Order now

Perks of our essay writing service

We offer more than just hand-crafted papers customized for you. Here are more of our greatest perks.

  • Swift delivery
    Our writing service can deliver your short and urgent papers in just 4 hours!
  • Professional touch
    We find you a pro writer who knows all the ins and outs of your subject.
  • Easy order placing/tracking
    Create a new order and check on its progress at any time in your dashboard.
  • Help with any kind of paper
    Need a PhD thesis, research project, or a two-page essay? For you, we can do it all.
  • Experts in 80+ subjects
    Our pro writers can help you with anything, from nursing to business studies.
  • Calculations and code
    We also do math, write code, and solve problems in 30+ STEM disciplines.

Frequently asked questions

Get instant answers to the questions that students ask most often.

See full FAQ
  • What if I’m dissatisfied with the paper I get?

    The average quality score at our professional custom essay writing service is 8.5 out of 10. The high satisfaction rate is set by our Quality Control Department, which checks all papers before submission. The final check includes:
    • Compliance with initial order details.
    • Plagiarism.
    • Proper referencing.
    If for some reason we happen to leave a mistake unnoticed, you are invited to request unlimited revisions of your custom-written paper. For more information, check our Revision Policy. We will do our best to make your experience with Familiar Essays enjoyable.
  • I need an essay on the same day. Is it something you can do?

    Sure. Our writing company offers a fast service with an 8-hour deadline for orders up to master’s level. Make sure to specify the deadline in the order form and our writers will write a paper within the indicated timeslot. Just proceed to submit your requirements here Once you order a custom-written essay, our managers will assign your order to the well-suited writer, who has the best skills and experience for preparing your specific assignment. You can also request one of these extra features:
    • Choose the Writer’s Samples option – study 3 randomly-provided pages from orders that have been written by the assigned writer.
    • Request a specific writer – choose an academic writer from the dropdown list in the order’s form (optional for returning customers).
    You can be sure that your custom writing order will be accomplished by one of our 400+ professional academic writers. They all pass a series of tests to prove their writing prowess and hold the reputation of being the most professional in the industry. Want to make sure writer’s skills match your needs? Get more details on how to choose the appropriate author.
  • How can I be sure your writing service is not a scam?

    We understand that a shade of mistrust has covered the paper writing industry, and we want to convince you of our loyalty. Apart from high-quality writing services, we offer:
    • The chances of students to boost writing skills in a quick and effective way.
    • The opportunity to manage studies and free time in an enjoyable manner.
    • The possibilities to improve overall academic performance.
    Our custom writing company has been working for more than 12 years and always puts quality and clients’ needs first. Our operations are legally documented, we are easily accessible online and offline,
  • Is it legal to use your professional writing service?

    Yes. Custom writing help is not prohibited by any university or college. It’s a 100% legal way of getting professional assistance with paper writing. Hiring writers from an essay writing company is in many ways similar to consulting a tutor – we help you solve the writing issues at hand.
  • How does your service work?

    Our custom writing service is a reliable solution on your academic journey that will always help you if your deadline is too tight. You fill in the order form with your basic requirements for a paper: your academic level, paper type and format, the number of pages and sources, discipline, and deadline. Then, you describe the specific details of the paper you need: add the topic, write or paste the instructions, and attach files to be used, if you have them. After that, an online customer support representative chooses the best writer that specializes in your discipline and assigns him or her to complete the paper according to your requirements. When the paper is ready, we check it for plagiarism and send it to you. If you want to change something, you can request a free revision.
See full FAQ

Take your studies to the next level with our experienced specialists

Live ChatWhatsApp