If online homeschooling is your choice, I have some great activities you’ll love. Here is one of those activities where I will teach you how to build your own pulley.
Shed 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 spool of wooden string and thread one free end of the freshly cut hanger wire through it (from left to right) and bend the free end. Now take the other free end and similarly pass it through the other side (from right to left) and fold the free end over. Make sure the spool can turn freely. You have now built a pulley.
Online homeschooling gives you the option to work at your own pace, so you should have fun with your pulley. Attach the hanger to a ceiling hook. Take a basket and tie a strong rope to its handle. Pass the rope over the pulley and pull on the free end of the rope to see if your pulley works. Feel free to put different weights on the basket and try to lift the basket by pulling on the free end of the rope.
Triple pulley system: You can build this pulley system in your backyard or under your tree house to bring food and other things to the tree house. Place two pulleys on top of each other on the tree branch. Attach another pulley with an S-hook to the basket handle. Now take a rope and tie one end to the handle of the basket. Thread this rope over the top pulley and then through the basket pulley and then over the bottom pulley. Tie the free end to a tube to make a handle.
Has the number of pulleys made a difference? to the effort you must exert to pull an object? Try to pull a weight using a single pulley system. Now pull the same weight on your triple pulley system. Do you have to use the same force?
You may have noticed that as the number of pulleys increases, less force is needed to pull the same weight. Does this teach you anything about how multi pulleys are used?
In the previous experiment I used three pulleys. This means that the weight is distributed among all three pulleys and therefore it will only take a third of the effort to pull the weight. If the object to be lifted is 90 lbs., you must 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 rope is 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 animation 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 thrown is divided into four parts. So, if you want to lift an object that weighs 100 pounds, you’ll need an effort equivalent to only 25 pounds (100 รท 4). In conclusion, if you want to lift 100 pounds with one hand, you will need 4 pulleys. Isn’t this interesting?
Get your free copy of the “Homeschool Parent’s Guide to Teaching Science” which is full of great science experiments and activities by clicking the link below.