Newton's 1st Law of Motion
An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
((This law is often called the Law of Inertia))
Inertia: The tendency of an object to resist any change in its motion
- The more mass an object has, the more inertia it has. Mass is a measure of the amount of inertia.
- What is harder to stop rolling down a hill; an elephant on roller skates or a mouse on roller skates? The elephant! Why? More mass means more resistance to changing the motion (slowing down)
Examples of Newton's 1st Law of Motion
- Video - Football: Players in motion will stay in motion at the same speed and direction until acted on by an unbalanced force... the tackle!
- Video -Tablecloth Trick: Objects on the table cloth which are not moving will stay not moving so long as no unbalanced forces act upon them.
- Video - Egg Drop Trick: The eggs are not moving and will stay not moving so long as no unbalanced forces act upon them.
- Tricks We Did In Class:
- Pen/highlighter and hoop.
- Catching the quarter/washer from on your elbow.
- Dislodging the bottom washer from a stack of washers.
- Dollar bill pulled out from two bottles.
- Beads spilling out of a jar.
- Index card and a penny/quarter/washer.
- Real Life Examples:
- The head of a hammer can be tightened onto the wooden handle by banging the bottom of the handle against a hard surface.
- To dislodge ketchup from the bottom of a ketchup bottle, it is often turned upside down and thrusted downward at high speeds and then abruptly halted.
- When a car stops suddenly, anything not tied to the car (seat belt) continues to move forward and into the dash board or windshield.