Factors affecting bridge strength

Materials list
• Simple Building Materials Kit (TB27626)
• Drilled Tongue Depressors, box of 500 (5500190) (drill a hole near each end to put a brass fastener through)
• Brass Fasteners (brads), pkg. of 25 [K01662(P)]
• Pictures of Different Bridges
• Drawing Paper
• Pencils
• Crayons or Colored Pencils
• Rulers
• Graph Paper, pad of 50, 81/2″ x 11″ sheets (9706099)
• Plastic Straws, straight, 30 per group
• Scissors
• Masking Tape
• Pennies or Metal Washers (at least 300 for weight)
• Paper or Plastic Cup
• Stacks of Books