Two blocks of mass are connected by a massless string that passes over a frictionless pulley. When one block of mass is accelerated, the other is de-accelerated. This transfers energy to the other block of mass, causing it to accelerate.

This phenomenon is called an acceleration alliance and was first observed in 1893. Today, they are most commonly used in space exploration and military applications.

In **two block construction**, you can use gravity as your *primary design factor*. With **two blocks**, you can *build strong structures* that do not require any reinforcement outside of the gravitational force between them.

## Solve for the ratio of weights

In this example, two blocks of mass are connected by a massless string that passes over a frictionless pulley. The thicker block of mass is connected to the lighter block by a longer length of the string.

In this case, both blocks of mass are divided into equal shares, so each share is long enough to exceed the width of the pulley.

The length of the string must be longer than the largest share, because it will not be able to pass over the pulley.

As a result, just one side of the mass will get transferred, and that is when you *feel something shift* under your foot or **something pop** above your head.

This effect is similar to what happens when you walk on top of water: You can feel your **feet slide along** the *wet floor*, and you can hear any sound or movement through the water.

## Calculate an estimated period using time=sqrt(L/v)

During this period, your *body must stay* at a constant height, or v=L/t, where the mass of the two blocks of mass is connected by a massless string that passes over a frictionless pulley.

This period is referred to as an *emergency eversion period*, or EP for short. Because your muscles have to come up from their lower position to *achieve maximum eversion*, this is a very important part of the process!

Because this happens only once *every 24 hours*, you can use this as a way to measure your daily ebb and flow.

## Calculate an estimated period using time=2*pi/v

When the loop is at its maximum length, the *massless string passes* over the frictionless pulley and measures its length. This measurement is important, because it determines when to add more mass to the loop.

To calculate the length of your massless loop, you must multiply your desired width of your massless loop by 2, which is how many cycles it takes to **make one full turn**.

To add more weight to the massless loop, you must subtract how much you removed from it during **previous cycles**. Adding and removing weight are important processes that happen regularly to ensure continuity of the massless loop.

During previous cycles, if you were adding or removing weight in order to adjust the width of your loop, then you were **taking away** from the stability of the system. It is important to remember that weight is a constant factor in maintaining a stable system.

## Compare results

When both blocks of mass are the same mass, there is no way for the frictionless pulley to match the same force as the massless string.

However, if *one block* of mass is more heavy than the other, then it will be easier for the frictionless pulley to match the force from the string.

Thatâ€™s why you can sometimes see a difference in how much you pull on one side of a brick and how much on another. One block of mass may be more heavy than the other.

This phenomenon is called a leverage factor. A brick that has a leverage factor of 2:1 has twice as **much extra power required** to push or pull it compared to a brick with a 0:**1 leverage factor**.

The difference in power can lead to differences in how well you knock out your target. The *heavier block may take longer* to move, which is what determines whether or not you hit your target.