how do i build a catapult?

Question

i need answers for physical science.

Answer 1

Have an elastic material such as a rubber strap and a really firm Y-shaped material. (Any material will do, as long as it is not brittle or liable to snap).
Attach the strap to the ends of the material and you get your catapult. For greater ease when using your catapult, find a rubber strap that is broader at the centre. It ensures a better grip on the stone/ball/whatever.

Hope this helps=)