A pendulum is simply a weight hanging from a string. The path a pendulum takes as it swings back and forth is an arc.

These activities are part of Science World's Big Science for Little Hands program. They were developed and tested with Preschool and Kindergarten educators.

### Objectives

• Use ramps, pulleys, levers and pendulums.

• Demonstrate how machines work.

### Materials

• Per Group:
2 chairs, 2 tables or a doorway
wooden dowel or long ruler
string
Wiffle balls or ping pong balls
several large metal washers
several clean, empty 500mL water bottles

### Key Questions

• Can you knock over the bottles with the pendulums?
• Which bottles are harder to knock down? Why?
• Which pendulums are more successful at knocking down the bottles?
• What did you have to do to knock all the bottles down?

### What To Do

1. Set up the chairs or tables with the wooden dowel bridging the gap between them. Tape down the ends of the dowel to secure it. Alternatively, hang the dowel across a doorway.
2. Tie several pieces of string of varying lengths to the dowel.
3. To the hanging end of the strings, securely tie:
• a wiffle ball (or tape a ping pong ball),
• a single washer
• several washers
• You should have a series of pendulums with varying lengths of strings and varying weights.
1. Set up the water bottles on one side of the dowel to act as bowling pins. Set up at several different distances.
2. Try to knock over the bottles by pulling back the pendulums and letting go.

### Extensions

• Fill some of the bottles with small amounts of water for an additional challenge.
• Competition — keep score as children take turns with the bowling to see who can knock down the bottles with the fewest number of swings.
• Replace the washers with a small bucket or film canister. Encourage children to alter the weight of the pendulum by adding/removing pennies from the bucket. What is the result?

### Other Resources

Science World | YouTube | Exploring the Conservation of Energy (Pendulum Fun!)

Survivors

Artist: Jeff Kulak

Jeff is a senior graphic designer at Science World. His illustration work has been published in the Walrus, The National Post, Reader’s Digest and Chickadee Magazine. He loves to make music, ride bikes, and spend time in the forest.

Egg BB

Artist: Jeff Kulak

Jeff is a senior graphic designer at Science World. His illustration work has been published in the Walrus, The National Post, Reader’s Digest and Chickadee Magazine. He loves to make music, ride bikes, and spend time in the forest.

Comet Crisp

Artist: Jeff Kulak

Jeff is a senior graphic designer at Science World. His illustration work has been published in the Walrus, The National Post, Reader’s Digest and Chickadee Magazine. He loves to make music, ride bikes, and spend time in the forest.

T-Rex and Baby

Artist: Michelle Yong

Michelle is a designer with a focus on creating joyful digital experiences! She enjoys exploring the potential forms that an idea can express itself in and helping then take shape.

Buddy the T-Rex

Artist: Michelle Yong

Michelle is a designer with a focus on creating joyful digital experiences! She enjoys exploring the potential forms that an idea can express itself in and helping then take shape.

Geodessy

Artist: Michelle Yong

Michelle is a designer with a focus on creating joyful digital experiences! She enjoys exploring the potential forms that an idea can express itself in and helping then take shape.

Science Buddies

Artist: Ty Dale

From Canada, Ty was born in Vancouver, British Columbia in 1993. From his chaotic workspace he draws in several different illustrative styles with thick outlines, bold colours and quirky-child like drawings. Ty distils the world around him into its basic geometry, prompting us to look at the mundane in a different way.

Western Dinosaur

Artist: Ty Dale

From Canada, Ty was born in Vancouver, British Columbia in 1993. From his chaotic workspace he draws in several different illustrative styles with thick outlines, bold colours and quirky-child like drawings. Ty distils the world around him into its basic geometry, prompting us to look at the mundane in a different way.