I built a trebuchet for my dynamics project. To construct my trebuchet, I used 12 1”x 4” boards, a three pound lead weight, all thread, nuts, washers, a hook and eye, string, a miter saw, a circular saw, a drill, and a protractor. I chose to launch a tennis ball. Using the conservation of energy, I approximated the tennis ball to be released at 11.4 feet per second. In order for this to be possible with a distance of 15 feet the ball would have to be in the air about 1.32 seconds. So the acceleration of the ball would have to be decreasing at a rate of 8.63 feet per second squared. I used the following equations to help me determine the above numbers:

mgh= ½ mv^2

x = xo + vt

v = vo + at

After I finished building the trebuchet, this is what it looked like.

I wanted the tennis ball to cover approximately 15 feet, and I wanted to have a relatively small trebuchet. My trebuchet ended up being about 2 feet tall. The release arm was 3 feet long, and the sling and string combination was 18 inches.

The total distance achieved by the ball was 18 feet. The ball was in the air for about 1.5 seconds. The experiment was successful. I learned a lot about woodworking in the process of doing this project.