Mr. Petric, STEM Club. This week students showed how their designs changed. In week 1, they made a simple catapult, meaning it only contained 1 simple machine. In week 2, they were asked to add another simple machine to their initial design to either increase mobility, ease of use or distance. Most students chose to increase their catapults throwing distance, incorporating an inclined plane to the base. Combining more than 1 simple machine together turned their simple catapults into compound catapults.