Tuesday, July 6, 2010

Exploring Pulleys...

Here is another chance to engage the natural curiosity of your Kid Scientist. 

Ages: Big Kid scientists will be able to describe the action of pulleys better as well as how they operate as a Simple Machine but Little Kids will also be able to explore at their own level.

Materials:  Pulleys, string or yarn, container & weights (the Science Mommy used a paper cup and rocks), a spring scale if you have one

Purpose: This exploration is designed to introduce Kid Scientists to Simple Machines.  Simple machines use mechanical energy to make work easier. Big Kid scientists may want to do some research on simple machines to learn more about the energy transfer within simple machines (look in the Kid Science Links).  There are three basic types of pulley systems.  The Science Mommy will introduce each one, the Kid Scientists can take their explorations as far as their questions will take them.

  • A spring scale will help determine if the pulley system reduces the amount of effort required to lift the load.  All of these pulley systems can also be explored without a spring scale.
  • Create a load.  The Science Mommy attached yarn to a paper cup and filled the cup with rocks.

    A fixed pulley is located above the load.  String is attached to the load and threaded through the pulley.  Pulling on the string uses the pulley to help lift the load up to the pulley.

  • A moveable pulley  is located on the load.  String is attached above the load, threaded through the pulley and pulled upwards to life the load. 

  • A block and tackle  or combination pulley system uses both a fixed pulley and a moveable pulley.  The string can either be anchored above the load or attached to the load.  Then it's threaded through the pullies. 

Questions to Explore:
How does one pulley work?
Does the size of the pulley matter?
Does the length of the string affect the pulley system?
What is the best way to use a pulley?
What is the most efficient pulley system?
Are there any disadvantages to using a pulley?
Where can you find examples of pulley systems in the "real world"?

Share what you learn with the Science Mommy!


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