La"BALL"atory

Create Something

At Home

At the Bernoulli blower, when the plastic ball is resting on your hand, air is pushing in on all sides of the ball with the same force. As you start moving your hand (and the ball) into the air stream, there is reduced pressure on that side of the ball. Move the ball far enough into the air stream and there is such a difference in pressure that the still air on the back side of the ball pushes it off your hand and into the air stream.

You can do the same thing at home with a funnel and a ping pong ball!

How To:

1. Place a ping pong ball inside a funnel.
2. Blow through the bottom of the funnel and try to blow the ball out. Try as you might, it won't come out!
3. Now blow very hard over the top of the funnel. What happens?
4. Try turning the funnel upside-down and blowing. Can you keep the ball inside the funnel?

At School

Lesson: Students will make balloon rockets to demonstrate Newton's second and third laws.

Materials:
string (approximately 10 feet for each group)
long balloon for each student
straw for each student
tape
paper clips

How To:

1. Tape one end of each string to the wall.

2. Give each student a long balloon, a straw and some paper clips.

3. Instruct the students to take turns launching their rockets. They should blow up their balloons and then tape the straw along the length of the balloon, end to end. Holding the balloon closed, they should carefully thread the string through the straw. When they let go of the balloons they will launch along the string.

4. Make sure they are holding the string taut, or the balloon won't go very far.

5. To make the balloons go even farther they can use the paper clips to hold the end of the balloon closed enough so that the air will go out slower. This will slow down the balloon, but it should go farther.

6. Discuss Newton's second and third laws. Newton's second law states that a force on an object will cause it to accelerate in the direction of the force.

Newton's third law states that for every action there is an equal and opposite reaction.

Academic Concepts:

Science - Physics