Tennis Ball Catapult

Q: Can you clarify what the following mean “The last point on the device touched by the tennis ball may not be more than 50cm above the ground....”? (section: The Competion explanation / paragraph: #3 / sub-paragraph:  / line: Line #2 )

A: What ever part of the catapult that last touches the tennis ball cannot be more than 50cm above the ground. For example, if a swinging arm is used the part that touches the tennis ball cannot be more than 50cm above the ground at any point as it swings. If some other design is used, the same rule applies and the part where the tennis ball last touches the device must be no more than 50 cm above the ground.