Friction in Water & Air

TOPIC: Principles of Flight: Newton's First Law of Motion
LEVEL: Advanced

"Friction in Water & Air"

CONCEPT:: Newton's First Law of Motion: objects at rest remain at rest and objects in motion remain in motion unless acted upon by an outside force.
STUDENT OBJECTIVE:: The student will discover that friction is an outside force that acts upon motion to make things slow down.
OVERVIEW:: The student will use bowls of water and balls to discover that friction acts upon motion to slow it down.
TEACHER TEXT:

PREPARATION TIME: 5 minutes

LESSON TIME: 10 minutes

TEACHER PREP:

Gather materials

MATERIALS NEEDED:

STEPS TO FOLLOW:: 1. Half fill each bowl with water.; 2. Place a ball in each bowl.; 3. Try spinning each ball in the bowl.; 4. Observe what happens. (The smooth ball spins more quickly and easily.)

WHY?: Friction is the force that occurs when two things rub together. In this case, the smooth surface causes less friction, so the rubber ball moves more easily and quickly than the tennis ball. The tennis ball, with its rougher surface, moves more slowly and awkwardly. This is why fast boats and airplanes have streamlined, smooth bodies.

ASSESSMENT: Can the student communicate what they observed?: 4......Student is able to communicate that the rubber ball moves more quickly and easily because of less friction.; 3......Student is able to communicate that the ball with the smooth surface moved more quickly and easily than the ball with the rough surface.; 2......Student is able to communicate that one ball moved faster than the other.; 1......Student is able to communicate that the balls moved.