Our superhero dashes through the landslide tossing huge rocks aside as if they are tiny pebbles. Finally, arriving just in time, our hero catches a mighty boulder in midair, saving a terrified victim from its crushing blow. If you've seen any of the Superman movies, you've seen actor Christopher Reeve perform feats of strength even more amazing than boulder-tossing. Can he really be that strong? To find out more, set up the "Big Rock Challenge" with your friends.
Curious for an answer? Look Behind the Scenes.
- You will need: a yardstick, string, tape, a real rock (2 or 3 inches across), an assortment of large plastic foam pieces left over from packing cartons, and toothpicks.
- The idea of the challenge is to create the biggest boulder possible with the same mass as the rock. A balance, made from the yardstick, will be used to compare the real rock to the special effects boulders.
- Build a balance like the one shown on this page to compare your prop rock to the real thing.
- With a piece of string and some tape, suspend the rock from the 1-inch mark at one end of the stick. Hang all of the boulders you create from the 35-inch mark at the other end.
- Build your first boulder from plastic foam. You can fasten pieces together with toothpicks or tape and tear chunks out to lessen the size or improve the look. Then hang your boulder opposite the rock on the balance. Add or subtract foam until the yardstick is parallel to the floor and the two have nearly the same mass.
- What clues does your plastic foam boulder give you about the rocks used in the movies?
- Does your prop look enough like a boulder to be believable? What else would you need to do to make this special effect do the job?
- What other materials or designs could you use to build a better boulder and beat the Big Rock Challenge? You might try papier-mâché, hollow objects, or different kinds of foam.
- How would you need to handle this prop rock for the action to look realistic?
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