Pulleys Please!

What You Need:
  • Empty spools of thread
  • String
  • Items to pick up such as a bunch of pencils
  • A pulley pal
Question: How do pulleys help you to do work?

1) First, tie a heavy object such as a bunch of pencils to one end of a string .

2) Then, raise the bunch of pencils off the floor by pulling directly up on the string. Notice the weight of the object as you pull up .

3) Now, put the pencil through the empty spool of thread. Then loop the string over the pencil.

4) Have your pulley pal hold the pencil and spool in the air.

5) Pull one end of the string down. Notice the weight of the object as you pull on the string and it raises into the air.

6) What do you notice about the amount of effort, or work, it takes to lift an object with a pulley?

A Scientific Explanation:
We use machines such as pulleys to make our work easier. When you lift the object without the pulley you work with one rope. When you lift with the pulley, it is like working with two ropes. One side of the rope goes up the pulley, and the other side goes down. By using a simple pulley you can divide your work in half!

EXTRA! EXTRA!
Have your friend hold a second pencil with a spool of thread under the first. Loop the string around the two spools. Do the experiment again. What do you notice about the amount of work it takes? Was it harder or easier with two spools? Can you explain what happens?

Experiments

  • Pullys Please!
  • Honey-Comb Bones
  • Follow the Flickering Firefly
  • Take an Ant to Lunch
  • Fossil Fun!
  • Suspend Metal in Mid-Air!
  • Clickety Clack: The Transfer of Force
  • Make Rain Indoors!
  • Eruptions of Color!
  • Wacky Water
  • Tiny Tornados
  • Fantastic Fingerprints
  • Mirror,Mirror on the Wall
  • Bubble Fun
  • Meteorite Beach
  • Rock Shard Puzzle
  • Tweet Tweet Tweet! Bird Sounds
  • Sound and Vision!
  • Super Science in Your Own Backyard
  • Grow Your Own Crystal Candy
  • Ant Antics
  • Make Carbon Dioxide
  • Battle Beetles!
  • Seashells by the Seashore
  • Race the Moon
  • Capillaries in Action
  • Shoebox Dig
  • Backyard Dinosaurs
  • The Incredible Egg
  • Icebox Erosion
  • Make a Rainbow
  • Aqua Vision

Back to Games & Activities

This site contains information and advertising about Scholastic and third party products.