Newton's First Law: Exploring Inertia
Grade 8 Physical Science Understanding Objects in Motion and at Rest
Think About This...
What happens to your body when a car suddenly stops? Why do objects on a table stay in place? What makes a rolling ball eventually stop?
Newton's First Law of Motion
An object at rest stays at rest An object in motion stays in motion Unless acted upon by an unbalanced force This tendency is called INERTIA
Hands-On Investigation
Work in groups of 5 students Use ramps and toy cars to test inertia Vary the ramp height Observe what stops the car Record your observations
Objects at Rest vs. Objects in Motion
{"left":"Book sitting on a desk\nBall balanced on a shelf\nCar parked in a driveway\nPencil lying on paper","right":"Hockey puck sliding on ice\nCar driving down a highway\nBall rolling across the floor\nSatellite orbiting Earth"}
Real-World Examples of Inertia
Passengers in a braking car lean forward A tablecloth pulled quickly leaves dishes in place A coin stays put when paper is pulled from under it Ice hockey puck slides until friction stops it
Create Your Inertia Chart
Column 1: Your experiment description Column 2: What motion did you observe? Column 3: How does Newton's First Law explain it? Column 4: Real-world example that matches
Remember This Key Concept
"Inertia is the tendency of objects to resist changes in motion. Objects at rest want to stay at rest, and objects in motion want to keep moving in the same direction at the same speed."