Newton's First Law of Motion states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force.

To make an object travel in a circular path a centripetal force is required, in this acitiviy that force is removed, so the marble continues on a straight path.

Inertia causes this straight path to continue when we remove the centripetal force.

Inertia is the resistance of any physical object to any change in its velocity. This includes changes to the object's speed, or direction of motion. An aspect of this property is the tendency of objects to keep moving in a straight line at a constant speed, when no forces act upon them.

### Objectives

• Describe a scenario that demonstrates the property of inertia.

### Materials

• Per Group:
paper plate or aluminium pie pan with section cut out
marble

### Key Questions

• What direction does the marble travel in when it reaches the gap? Why?

### What To Do

Challenges students to roll a marble along the side of the pie pan in such a fashion that it leaps over the gap and continues it’s circular path.

### Extensions

• Draw a free body diagram for circular motion.
• What changes when the size of the gap in the pie plate is larger or much smaller?
• When you a travelling in car and it takes a corner at speed, what does it feel like? Why?

### Other Resources

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.