"Rocket Balloon"

Newton's Third Law of Motion
    This law states that when an object applies a force onto another object, the other object             pushes back with an equal force in the opposite direction.

The Materials needed:

            

            Balloons                          String                         Straws                         Scotch Tape

Steps:

    Get into groups of 3

1. Cut a piece of string at any length, depending on how far you want to see it go.

2. Put the string through the straw and have two students hold on to each end of the string.

3. One person will blow up a balloon and hold it so that no air is able to release and tape it to       the straw so that one end of the straw points to the neck of the balloon.

4. While holding the balloon shut slide the balloon to the end of the string, make sure the neck       of the balloon is also pointing in the same direction. 

   It should look like this...... 

5. Let go of the balloon and see what happens.

    The balloon should fly to the other end of the string as it deflates. The reason is because when letting go of the balloon the air is pushed out of the neck. The air pushes on the balloon with equal force in the opposite direction, making the balloon travel across the string.

Some Tips:

• Before  starting the experiment you could ask the students to define Newton's Third Law of Motion.
• After the experiment some questions that can be asked:

            - What cause the balloon to travel across the string?
            - Would it make a difference in speed, or how far the balloon travels if you use a different type of string?
                      Such as ribbon.....
                                                     

References:
http://physics.about.com/od/classroomphysics/ss/balloonrocket.htm

http://www.csiro.au/csiro/channel/ichr.html

Picture:
http://www.wrapwithus.com/img/500_yard_ribbon/large/light_blue.jpg