In this activity, students will understand how potential energy is stored and converted by observing a slinky and a spring in action.

Elastic potential energy is energy stored in objects by tension (like a stretched rubber band) or compression (when you squeeze a spring).

When the potential energy is 'released', it is converted to the energy of motion, also known as kinetic energy. This is the energy you see when the rubber band or spring pops back to its original shape.

Vocabulary:

Compression: Any of the forces applied towards the centre of structural objects. An engineering term used opposite to tension.

Tension: A force tending to stretch or elongate something. A term used opposite to compression.

### Objectives

• Use a model to explain how potential energy transfers to kinetic energy.

### Materials

• Per Class or Group:
3 or 4 large commercial springs
several small spings (optional: they can be collected from used pens)
small weights in regular increments (5 g, 10 g, 15 g, etc.)

### Key Questions

• What happens to the potential energy stored in the stretched Slinky when we let go of it?
• If we stretch the Slinky even further, do you think it will spring back faster or slower? Why?
• What happens to the springs when we attach the weights to them? Which spring stretches the furthest?
• Which spring stores the most potential energy?
• Which spring would spring back the fastest if the weight were taken off? Why do you think so?

### What To Do

Part 1: Demonstrate, or have students demonstrate, the following with each of the items.

Teacher Tip: Encourage students to ask questions, make predictions, and discover the conclusions themselves.

• Have 2 volunteers hold either end of one Slinky and stretch the Slinky by slowly backing away from one another. Watch what happens when it’s released.

Spring:

• Hold up the springs and observe what happens as you hook the small weights (of varying mass) to each.

### Extensions

• Where there any unintended energy conversions? What where they?

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.