During our physics class, while we were learning acceleration,speed,force, and etc.. We decided to build a catapult since the arm puts acceleration,speed, and force into the invention. So our class decided to test how far we can launch the golf balls by building a mini- catapult (because of the small doors) also we could design it anyway we wanted. But first we needed to know what we were going to bring, so for ours we had at least 4 large 2X4's, a can for the "hand", a metal pipe for the arm, 2 large springs, and a steel pipe for latching the springs with the pipe. Also we tested our catapults acceleration and it came up to 125 m/s squared. Which the according to Newton's Second Law the golf ball's distance should've went about 76 but our final was 22.8m which was less then we expected out of our catapult. So this is how we built it:
Step 1: How to start it
To build the catapult we had to build it by using 2 out of the 3 large 2X4's, cutting both into 2 90inches and 140 inchs. both 140 inch boards are the length and the 90's as width. After cutting them, we screwed them together with metal brackets in each corner just to make sure they wouldn't move.
Step 2: Slowly but surely getting their
The next step we did was to cut the 3rd large 2X4 into 2 one and a half foot boards. These boards are to attach to the inside so we can put the 2 pipes in.After attaching them vertically to the inside of the base, we drilled them down to the base with 2 more metal brackets. Also we had to drill holes starting from the top we went 10inchs down and drilled a hole then the 2nd hole was at 37 inchs.