TRANSFORM ENERGY TO MAKE FOOD FLY.
MATERIALS
Rubber bands
Plastic or rubber ring (such as the kind you find on the neck of a prescription bottle or under the lid of a plastic milk jug)
Marshmallows
Chair with legs
SAFETY
TIPS & HINTS
Shoot marshmallows at targets, not each other. Stale marshmallows are less sticky and are easier to launch.
STEP 1: Attach two or more rubber bands to the ring (you can double it to make it stronger) with the ring in the center. You can link two rubber bands by overlapping them slightly, and pulling the bottom one through the one on top and then through itself. Attach them to the ring the same way. (Fig. 1, 2)
STEP 2: Set up your slingshot on a chair by turning the chair over and stretching the rubber bands between the legs, with the ring in the center. (Fig. 3)
STEP 3: Use your slingshot to shoot marshmallows at a target and watch as the elastic energy in the rubber bands turns into kinetic energy, which is the energy of motion. It may take some practice, but before you know it, you’ll be a confectionery sharpshooter. (Fig. 4)
THE SCIENCE
BEHIND THE FUN:
Energy changes, but it doesn’t go away, it transforms. This scientific concept is called the transformation of energy. When you pull the rubber band on your slingshot back, your muscles do work on the rubber band. How much work you do depends on how hard you pull on the rubber band (force) and on how far back (the distance) you pull the rubber band. Work = force × distance.
The work you do is stored as elastic energy in the rubber band. When you release the rubber band, the rubber band does work on the marshmallow and the elastic energy is transformed into kinetic energy (the energy of motion) in the flying marshmallow. When the marshmallow hits something and stops, the kinetic energy is transformed into heat energy.
CREATIVE
ENRICHMENT
Does the thickness of your rubber bands affect how far you can shoot an object? Why?
What other variables affect the distance and direction of your marshmallow’s flight?
