If online homeschool is your choice, I have some great activities that you will love. Here’s one such activity in which I will teach you to build your own pulley.
Hangar Pulley: Make a cut in the center of the base of a wire coat-hanger (imagine cutting the base of a triangle). Now take a wooden thread spool and pass one free end of the recently cut hanger wire all through it (left to right) and bend the free end. Now take the other free end and pass it in a similar way through the other side (right to left) and bend the free end. Make sure that the spool can turn freely. You have now built a pulley.
Online homeschool gives you the option to work at your own pace, so you must have some fun with your pulley. Fix the hanger to a ceiling hook. Take a basket and tie a strong string to its handle. Pass the rope over the pulley and pull the free end of the string to see if your pulley works. Feel free to put different weights in the basket and try pulling the basket up by pulling the free end of the string.
Triple Pulley System: You can build this pulley system in your backyard or below your tree house to get food and other stuff to the tree house. Attach two pulleys one above the other on the tree branch. Attach another pulley with an S-hook to the handle of the basket. Now take a rope and tie one end to the basket handle. Run this rope over the topmost pulley and then through the basket pulley and then over the lower pulley. Tie the free end to a pipe in order to make a handle.
Has the number of pulleys made a difference to the effort you must put in order to pull an object? Try pulling a weight using a single pulley system. Now pull the same weight in your triple pulley system. Do you have to use the same force?
You must have noticed that as the number of pulleys increase, it takes lesser force to pull the same weight. Does this teach you something about how multiple pulleys are used?
In the above experiment I have used three pulleys. This means that the weight is distributed among all three pulleys and therefore you will require only one third of the effort to pull the weight. If the object that has to be lifted is 90 lbs, you will have to apply a force equivalent to 30 lbs to lift the object.
This is called the mechanical advantage or leverage. Mechanical advantage can be determined by counting the number of parts the ropes gets divided into (not counting the part of the rope you are pulling). What does your online homeschool curriculum teach you about mechanical advantage? Do you have access to any animations to demonstrate the same?
If a pulley system has four pulleys the rope is divided into four parts (excluding the part you are holding). This means that the weight of an object to be pulled is divided into four parts. Therefore if you want to lift an object weighing 100 lbs, you would require an effort equivalent to just 25 lbs (100 ÷ 4). In conclusion, if you want to lift 100 lbs with one hand, you will require 4 pulleys. Isn’t this interesting?
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