More Pulleys Increase Mechanical Advantage

Let's see how the mechanical advantage increases when more fixed and movable pulleys are added to the compound pulley arrangement we’ve been working with.

The image shows a more complex compound pulley. To determine the mechanical advantage of this pulley, we need to determine the force, F₅, Mr. Toga exerts to hold up the urn.

The urn is directly supported by four equally spaced rope sections with tension forces F₁, F₂, F₃, and F₄. The weight of the urn, W, is distributed equally along the rope, and each section bears one quarter of the load. Mathematically this is represented by,

F₁ = F₂ = F₃ = F₄= W ÷ 4

If the urn’s weight wasn’t distributed equally, the bar directly above it would tilt. This tilting would continue until equilibrium was eventually established, at which point all rope sections would equally support the urn’s weight.

Because the urn’s weight is equally distributed along a single rope that’s threaded through the entire pulley arrangement, the rope rule, as I call it, applies. The rule posits that if we know the tension in one section of rope, we know the tension in all rope sections, including the one Mr. Toga is holding onto. Therefore,

F₁ = F₂ = F₃ = F₄= F₅= W ÷ 4

Stated another way, the force, F₅ , Mr. Toga must exert to keep the urn suspended is equal to the weight force supported by each section of rope, or one quarter the total weight of the urn, represented by,

F₅= W ÷ 4

If the urn weighs 40 pounds, Mr. Toga need only exert 10 pounds of bicep force to keep it suspended, and today’s compound pulley provides him with a mechanical advantage, MA, of,

MA = W ÷ F₅

MA = W ÷ (W ÷ 4)

MA = 4

It’s clear that adding the two extra pulleys results in a greater benefit to the man doing the lifting, decreasing his former weight bearing load by 50%. If we added even more pulleys, we’d continue to increase his mechanical advantage, and he’d be able to lift far heavier loads with a minimal of effort. Is there any end to this mechanical advantage? No, but there are undesirable tradeoffs.

Comments

Team Work - Meaning and Tips for better Team Work

A single brain is not always capable of making key decisions on its own. To come up with an efficient solution, an individual requires the help and advice of others. A team is established when individuals get together on a common platform with the common goal of completing a task. To guarantee optimum compatibility, team members should ideally come from similar backgrounds and have a single aim. To provide their best, the team members must complement each other and function as a single unit in tight cooperation. "There is no I in Team Work," as the saying goes, and each member must put the needs of his team first. Personal interests must take a second seat. Any team's performance is directly proportionate to the relationship between its members and their combined efforts. What is the definition of teamwork? Teamwork is defined as the sum of each team member's efforts toward the fulfilment of the team's goal. In other words, any team's backbone is its ability t

Scientists discover a new theory / The fundamental property of light – 150 years after Maxwell

Light plays a vital role in our everyday lives and technologies based on light are all around us. So we might expect that our understanding of light is pretty settled. But scientists have just uncovered a new fundamental property of light that gives new insight into the 150-year-old classical theory of electromagnetism and which could lead to applications manipulating light at the nanoscale. It is unusual for a pure-theory physics paper to make it into the journal Science. So when one does, it’s worth a closer look. In the new study, researchers bring together one of physics' most venerable set of equations – those of James Clerk’s Maxwell’s famous theory of light – with one of the hot topics in modern solid-state physics: the quantum spin Hall effect and topological insulators . To understand what the fuss is about, let’s first consider the behaviour of electrons in the quantum spin Hall effect. Electrons possess an intrinsic spin as if they were tiny spinning-tops,

19 Types Of Content Writing Services For Your Business

It’s hard to know which type of content writing service is the best for your business. There are so many different types of content writing services out there that it’s easy to get confused. You end up wondering if you’re choosing the right one for you. In this post, we’ll get rid of this confusion, once and for all. I’m going to list out the different kinds of writing services you could use. By the end of this article, you’ll know whether you need a copywriter, a content writer, or a social media marketer and how they can help you achieve your business goals. This post is also useful for writers who want to hone their writing skills in a specific area. Let’s dive in and learn what types of content writing services exist and when you should use them. (Bonus – if you want to hire the top 1% of writers, go to the bottom to learn how). Types of Content Writing Services As we go through the list of content writing services, you will find that many of them overlap. That’s perfectly

The LimitlessX - Get Tech Science News around the Globe

Search This Blog