FRICTION THROUGH WATER

MATERIALS

Wide-mouthed see-through jar, or empty tennis ball can
Clay
Water

PROCEDURE

1. Add water to your container until it is almost full.
2. Take a small amount of clay and roll it into two small balls.
3. Take one of the balls and flatten it like a small pancake. Leave the other piece round and smooth.
4. Hold both pieces of clay just above the surface of the water. Ask, “Which piece of clay do you think will drop the fastest?”
5. Now drop both pieces of clay through the water at the same time. Observe. Discuss. What role did friction play with the different speeds of the clay?


EXPLANATION

Friction is the resistance of motion on the surface of a body. The more surface, the more friction, the more resistance to motion. Fish and boats are streamlined to reduce their surface so they can speed through water more easily.