## What is the formula for pulleys?

The equations, F(1) = T(1) – G(1) and F(2) = -T(2)+ G(2), assume the pulley has no friction or mass. It also assumes mass two is greater than mass one.

**How much weight can a block and tackle lift?**

Even though a block and tackle decreases the amount of force necessary to move an object, it does not change the amount of work. For example, a block and tackle with a mechanical advantage of four will allow you to lift a 4 lb. object with only 1 lb. of force.

**What is an example of a block and tackle?**

An example of a block and tackle is a method of hoisting up heavy blocks of metal using cables and pulleys. A system of two or more pulleys (the tackles) each enclosed by a housing (the block) with a rope or cable threaded between them, usually used to lift or pull heavy loads.

### How do you calculate mechanical advantage?

Calculating Mechanical Advantage and Efficiency of Simple Machines. In general, the IMA = the resistance force, Fr, divided by the effort force, Fe. IMA also equals the distance over which the effort is applied, de, divided by the distance the load travels, dr.

**How much weight does a pulley take off?**

You could say, in general, that the pulley load reduction is the reciprocal of the number of ropes supporting the load, but few practical pulley systems have more than four ropes. Consequently, the maximum pulley load reduction you can realize is one-quarter the weight of the load.

**Does a pulley cut weight in half?**

A pulley with one wheel allows you to reverse the direction of your lifting force by pulling down on a rope (that’s looped over the wheel), lifting your weight. With a two-wheel pulley, you reduce the effort you exert to lift the same amount of weight. You lift the weight with half the force.

## What is the difference between a pulley and a block and tackle?

On its own, a pulley can only change the direction of a force applied to an object. A system of pulleys working together can form a block and tackle, which multiplies force in addition to changing the force’s direction, meaning less force is required to move an object.