Newton's Third Law of Motion
To construct a car to demonstrate how rockets move by means of action
A small car is propelled by the action/reaction force generated
by a balloon.
BY: Gregory Vogt, OSU
BY: Roger Storm, NASA Glenn Research Center
- 4 pins
- Marker pen
- Small party
- Emery Board
- Using the
ruler, marker, and drawing compass, draw a rectangle 3 by 7 inches
and four circles 3 inches in diameter on the flat surface of the
meat tray. Cut out each piece. Use an emery board to make the
wheels as round as possible.
- Push one
pin into the center of each circle and then into the edge of the
rectangle as shown in the picture. The pins become axles for the
wheels. Do not push the pins in snugly because the wheels have
to rotate freely. Test them to be sure they rotate freely. It
is okay if the wheels wobble.
the balloon a few times to stretch it out a bit. Slip the nozzle
over the end of the flexi-straw nearest the bend. Secure the nozzle
to the straw with tape and seal it tight so that the balloon can
be inflated by blowing through the straw.
- Tape the
straw to the car as shown in the picture.
the balloon and pinch the straw to hold in the air. Set the car
on a smooth surface and release the straw.
The rocket car is propelled along the floor according to the principle
stated in Isaac Newton's third law of motion. "For every action there
is an opposite and equal reaction." The balloon pushes on the air
and the air pushes back on the balloon. Because the balloon is attached
to the car, the car is pulled along by the balloon.