You can easily make your own simple machines at home, to help your children learn to enjoy engineering their own solutions.
Wow! That’s easier. In our age of complicated machinery, it’s easy to forget that even the most complicated mechanics are just a large set of simple machines. We use complicated machines for parts of our lives, and too often stupidly grunt through tasks when a little bit of ingenuity would make the task much easier.
Pulleys can be used to make various types of elevators, or in converting fly wheels to useful energy as in an old fashioned mill.
Why pulley’s work
Pulley’s are used to redirect the the tension in cord of some kind . By allowing the work to be done in the same direction as gravity, They pulley allows an object to be lifted with less force. Every pivot point exerts upward force on the system, again decreasing the amount of force needed. Of course, all this decrease in force comes at a cost. Each pulley also increases the distance over which the force will need to be applied. These are all lessons your child can figure out for himself with his own pulley system.
Materials for making your own pulley
- Large box or sheet of cardboard.
- Cans of two different sizes from the recycle bin
- Yarn or rope
- A bottle of water
- Small bucket
- Weights. I used our Picasso Tiles, but any object would work. Rocks or Silver wear could be good solutions as well.
- Hot glue
Setting up the Pulley
If you are working with older students, allow them to set up their own pulley experiment by gluing the cans in what they think may be optimal positions.
If you are working with younger students. Glue the small cans in a couple of rows so that they can experiment by hooking up their pulley in various ways.
Place the larger cans over the smaller cans to make a pulley that turns easily.
Experiment with your pulley
Attach one end of the string to the bucket, and the other to the bottle off water.
Tell your child to draw a picture of your pulleys. In two different colors draw two different ways that the string could be looped through the pulleys. Write a paragraph explaining which set up will move more easily and why.
Loop the string over the pulleys
Add weights until the bottle of water moves. (Hint: Only fill the bottle half way for easier lifting.)
Try a different configuration and repeat.
After your child has experimented with a few different set ups, ask them to write a paragraph explaining how using more or less pulleys changes the force needed to lift something. Ask them to explain how the spatial relation of the pulleys changes things.
Take your pulley to the next level
If your child is ready for more of a challenge, ask him or her to engineer a system which uses pulleys and another simple machine such as a lever or zipline to move a cup of water from one point to another.
Can he or she think of an easier way to refill water glasses at the dinner table? Maybe when you’re outside for a picnic? What task can your inventor make easier with pulleys?
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