The document discusses the purpose and function of parachutes. It describes how parachutes use air resistance and gravity to slow falling objects by providing a large surface area to interact with the air. The document outlines an experiment to test how parachute size impacts falling speed by having students construct parachutes of varying circle sizes out of material and test their descent rates. It explains that too large a parachute falls too slowly while too small falls too quickly, and that air resistance and gravity work together to allow the parachute to float down instead of floating away.