Our mass launcher utilized a catapult-based launching mechanism in order to launch our golf ball as fast as possible. This design was not extremely structurally sound; however, it was extremely efficient in launching the golf ball due to the elimination of unnecessary weight/support structure.

In order to be as accurate as possible, we gathered our data by videoing our trials at 120fps. To find the speed, we measured out the ground distance of the ball release to first bounce, then found the actual distance traveled by the ball by using the Pythagorean theorem to find the hypotenuse of a right triangle that is 34cm tall (the height of our catapult arm) with a width of the ground distance traveled. We then multiplied the true distance by one over elapsed time and found our speed in cm/s, which we then converted to m/s. While this speed estimation technique was not perfect as it did not account for the parabolic curve of the ball, that extra distance was negligible and we felt that this technique was able to get the job done for us. 

You can view our raw data by navigating to this Google Docs.

In conclusion, I feel like our mass launcher was a success. We launched our golf ball at an average velocity of 6.6 m/s, much faster than what I expected when we started this project. If given more time I believe that we could have made several improvements to our design, namely more supports at the base and finding the optimal rubber band distance/arm length. Overall, my group worked very well with our time constraints and outputted a well-designed LEGO mass launcher capable of launching a golf ball at speeds upwards of 7 meters per second.