1. The problem statement, all variables and given/known data Hello!, Beforehand i want to thank you for taking your time to look at this. Here's the deal: There's a contest in my school for Science Fair. We have to make a catapult and throw tennis balls as projectiles. Here are the rules: 1) The catapult max measurements have to be 20 cm x 40 cm x 20 cm. 2) We have to get the biggest amount of tennis balls in 2 minutes in a trash can(diameter 28 cm, height 35 cm), which is 20 meters away from the catapult. 3) We cant use any bazooka or sling style. 4) NO explosives or combustibles. 5) We can use any type of structural material. 2. Relevant equations Any ideas? 3. The attempt at a solution None at the time of writing.