26 Sep, 2020


What are pulleys? How does a single movable pulley provide a significant mechanical advantage? Your inquisitive mind wants to know all the trifling matters of physics, right? A pulley is nothing but a robust mechanical device used to lift bulky objects without any hassle. Pulleys contain a wheel that revolves on an axle – it is a rod via the center of the wheel. That wheel not only revolves on an axle but also a rope, chain, and cable.

Thinking of theworking procedure of pulley? Here in this context, we will be going to discuss a single movable pulley and its mechanical advantage.

What is a single movable pulley?

A single movable pulley is an important classification of pulley that is free to move upwards and downwards. Whenever you are observing its structure, you will see, it is associated with a ceiling or other parts by two lengths of the analogous rope. Some leading examples of the single movable pulley are advanced elevators, weight lifting machinery at the gym, and construction cranes.

How does a single movable pulley work?

The mechanism is quite easy to understand. The wheel of a movable pulley is not associated with any stationary object. Albeit one end of the rope is a stationary substance.

In a single movable pulley, the load is appended to the wheel instead of a rope. Thereafter, the wheel moves abreast of the length of the rope as the weight is gradually lowered or lifted.

  1. Using the screws and drill to combine one fixed pulley to a point slightly off-center on one of your 2” * 4” plank.
  2. Now, feed the complete rope via the pulley.
  3. Feed a certain edge of the rope via a movable pulley.
  4. Thereafter, combine the end of the rope via a movable pulled to the 2” * 4” plank, about a definite 1 foot away from the fixed pulley.
  5. Now, establish the wooden plank in between two high surfaces so the pulleys are facing downwards.
  6. Next, combine the toolbox handles to the movable pulley.
  7. After that, add countless objects to make it bulky. Therefore, check the weight of the toolbox on the scale.
  8. Lift the toolbox by pulling down on the free end of the rope. Record those observations. How much can you raise with the help of the movable pulley?

What is the mechanical advantage of a single movable pulley in the ideal case?

A single movable pulley’s working technique makes it easier to lift bulky objects. By looking at the mechanical advantage, we ascertain a machine’s performance. A single movable pulley can efficiently raise those heavy objects with a significant amount of force than you applied to the rope. Therefore, the process is hassle-free for you to lift bulky objects.

How does a single movable pulley provide a mechanical advantage?

Pulley working procedure is quite a simplified action. It provides a mechanical advantage due to a constant tension force working throughout it. The pulley system possesses a simple rope or string, which can pull only and create tension. Compression does not take place here.

When a system is established as a single movable pulley, the weight you are lifting possesses the string-pulling up twice on the weight. It would be possible in weightless and frictionless pulleys if the object is having a weight of 20 Newton you can definitely pull on the strings with as meager as 10 Newton to lift the object. However, the tension force on the object is directed equally, horizontally, and oppositely cancels out each other unless the rope coming off the pulley.

It may seem to you that these forces are unbalanced. But when you think deeply, you will understand the ceiling is capturing a similar amount of force, which is helping to lift the object. Here rope is going through acute tension.

For example, ten powerful people pulling the rope from both ends, and when the other end is associated with a tree, those ten equally strong men pulling the rope on one end. Both cases seem equal, right? Therefore, when you establish the pulley system in this amazing way, you should assume the ceiling is another person.

Why is the mechanical advantage of a single movable pulley?

The formula of mechanical advantage is:

Mechanical Advantage = (Load to be carried) / (applied load)

Now, in the case of the single movable pulley, we may write:

L = T + T [Where L is load, and T is applied load]

Therefore, L = 2*T

M.A = L/T

= 2*T/T

= 2


Single movable pulleys provide you a significant mechanical advantage that means the force you put in is much lower than the force applied by the system. Moreover, this pulley can lift that object more efficiently than your force being applied on the rope. Therefore, it helps you to lift bulkier things effectively.

Get in Touch

Connect with us if you wish to discuss your next batch of job or next project

Need Help?