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The Great Bessbug Challenge
for Grades 4-6 How much weight can a bessbug pull? How do two bessbugs compare? Standards Science: Abilities to do scientific inquiry, understanding about scientific inquiry Life Science: Characteristics of organisms Math: Multiplying and dividing fractions or decimals Materials Two bessbugs; dental floss; sheet of construction paper; two 3" x 3" squares of aluminum foil; transparent tape; 200 pennies; large, shallow box (like a box lid); Lab Report Optional: a gram balance sensitive enough to weigh a penny, Helpful Hints Steps In a Nutshell Which bessbug will pull the most weight? How much will each pull? Work on a table. Tape construction to inside of box lids. Make a dental floss lasso for each bessbug. Tape other end of floss to foil squares. Place each bug in a box lid. Place 15 pennies on each square. Add more pennies until you reach the limit of your bessbugs' strength. Calculate the weight your bugs pulled and compare. The average bessbug weighs 1.5 grams. The average penny minted after 1982 weighs 2.5 grams. The foil and dental floss "sled" weighs about 1 gram. Safety Tips for Handling Bessbugs Bessbugs don't bite! Bessbugs travel slow! Wash your hands before and after handling bessbugs, for your safety and for theirs. Lift bugs by their abdomens (back section). To keep them from running off, lay bugs belly up in a shallow box. Be gentle. Don't rush. You might enjoy how a bessbug feels walking in your hand and up your arm. Detailed Steps 1. Get ready Print and copy the Bessbug Lab Report [Link to handout on separate page], one for each student. 2. Set up Students can help with the following. Cut two aluminum foil squares, 3 inches on each side. Cut two equal lengths of dental floss. Make two little lassos: tie a small loop in one end of floss; thread other end through the loop. Tape a piece of black construction paper at one end of the box. The paper will give your bugs a rough surface for traction. The black color will attract them. Divide pennies into stacks of 5. Set them near the paper towels. Decide which bessbug is A, which is B. Keep them in separate containers while you're going through the all the steps. Be sure to give each bug some wood and to keep wood moist. 3. Make predictions How many pennies do you think a bessbug can pull? Do you think one of your bugs can pull more pennies than the other? Write your prediction for each bug on the Lab Report. 4. Take measurements with a gram balance (Optional) If you prefer not to do the weighing yourself, use these numbers. Average weight of pennies minted after 1982 — 2.5 (2 1/2) grams Average weight of bessbugs — 1.5 (1 1/2) grams 5. Harness Bessbug A to sled Be careful not to mix up bessbugs as you go through steps 5, 6 and 7. Gently lay a Bessbug A belly up in the box. Slip the lasso over its abdomen and secure it around the waist, just above the wing covers (behind the first set of legs). Tape the loose end of the lasso to the bottom edge of a foil sled. Put 15 pennies in the sled. Gently place Bessbug A on its feet at the edge of the construction paper. 6. Test to see how many pennies Bessbug A will pull Put 5 more pennies in the sled. Repeat until Bessbug A can't pull more. Take out one penny at a time until it can pull again. Gently turn Bessbug A onto its back. Unharness it and return it to its container. Wash your hands! Count the pennies in the sled. Write this number on the Bessbug A result line of your Lab Report. 7. Repeat steps 5 and 6 with Bessbug B. 8. Do some math to analyze results First, figure out how much weight each bug pulled. Multiply number of pennies times the average weight of one penny. For example, if one bessbug pulled 34 pennies and if the average weight of a penny is 2.5 grams and if the sled weighed 1 gram, then the bessbug pulled 86 grams — (34 x 2.5 grams) + 1 gram = 86 grams. Figure out how many times its own weight each bessbug can pull. Divide the weight of the bessbug into the total weight of the pennies and the sled. For example, 86 grams ÷ 1.5 grams = 57 times its own weight! 9. If you were super strong If you had the pulling power that a bessbug does, how much weight could you pull. Multiply your weight times 57. WOW! Weighing Bugs and Pennies (Optional) Materials Gram balance, small dish (a plastic petri dish works nicely), 2 bessbugs, foil and dental floss, 10 pennies Pennies Weigh 10 pennies, one at a time. Average the weight of the pennies. Record and use as your average weight for each penny pulled by bessbugs. Sleds Each sled will be made of one piece of floss and one piece of foil. Weigh these together. Record weight. Repeat with second sled. Bessbugs Place dish on balance and weigh it. Place bessbug in dish and weigh dish and bug together. Subtract the weight of the dish from the weight of dish and bug together. This is the weight of your first bug. Repeat step 2 with second bessbug. Compare Human and Bessbug Pulling Power (Optional) How much weight can a human being pull? How would you investigate to discover this number? Work as a class to design an imaginary experiment. Choose an average age for your human being. How about 11 years old? Or 9, 10 or 12? Most children can't do one pull-up. They can't lift their own weight with the muscles in their arms. Using legs and backs, pulling a sled on a smooth surface, a child ought to be able to pull more than her own weight. How much more? How would you test to see how much weight you can pull? How would you find an average weight that an average kid your age can pull? How would you find the average weight of children your age? How would you figure out the pulling power of the average child? (Divide pounds pulled by average body weight.) What do you think is the most weight that a human being ever pulled? Find the answer at Guinness World Records! |
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