What we tested

We tested how the angle the arm was pulled back to would affect the speed of the object that was launched, which was a golf ball.

We took the catapult outside to test, then we pulled the arm back to -30 degrees then launched the catapult. Then we changed the angle of the arm to -40, and then -50. We measured the time from when the ball was launched to when it hit the ground, and the distance of which it was launched. Next we used that information to calculate the speed of the golf ball.