High school physics students learn about restoring force in an experiment that is inexpensive to set up and quick to complete. Bring a pot of water to a boil and pour the water into a graduated cylinder. Cut a rubber band so it lays flat. Tie one end around the center of a skewer and the other end to a lead fishing sinker or other small weight. Lower the weight into the graduated cylinder until the skewer comes to rest on the rim. Secure the skewer with two small lumps of modeling clay. Measure the temperature of the water. Measure the length of the rubber band between the skewer and the weight. Repeat measurements every five minutes until the water reaches room temperature. Drain out half of the water and fill the graduated cylinder with ice cubes. Resume measurements of temperature and stretch length in five-minute intervals until the ice melts. Graph the results to determine under what conditions the rubber band is most elastic.
Elementary children will enjoy conducting an experiment that can be eaten upon completion. Ask students to hypothesize how elastic a gummy worm is while distributing three candy crawlers, rubber bands, scissors and rulers. Instruct the students to cut a length of rubber band equal to the size of the gummy worms. Line one worm against the ruler and record its length. Stretch the worm as far as it will go without breaking and record the length. Release the worm and allow it to contract. Stretch the worm again and record its final length. Repeat the test on the other two worms to determine the average stretch length and compare it to the stretch length of the rubber band.
A simple experiment using common household items demonstrates the elasticity of air to elementary and intermediate students. Students inflate a balloon, tie off the end and press gently on one side. Teachers should ask students to observe and record what happens when they remove their hands from the balloon's side. Place a funnel in the open end of a second balloon and fill it with sand. Tell students to push against one side and record their observations about what happens when they remove their hands. Teachers can discuss the elastic properties of gas molecules in comparison to those of most solid molecules.
Science teachers will encourage experimentation and friendly competition while assisting students in understanding a fundamental physics concept by assigning students to create a vehicle propelled by elastic energy that will travel the farthest. Provide each student with a block of wood 7 inches long and 3 inches wide as well as several medium-sized rubber bands. Students may transform their blocks of wood into cars, boats, planes or trains; however, they may only be propelled by the energy stored in the rubber bands. Encourage students to research various strategies and experiment with several to achieve the greatest propulsion for competitive distance.