My topic is Trebuchets, and here's why. At first I was going to make a robot, but then Ben said we don't have enough time or parts. I had planned to make a catapult and make a robot to put it on. Then Ben said why not just make a trebuchet so again we got to work. A trebuchet is like a catapult except the force comes from a counterweight and not a spring.
The experiment was how does the weight of the load effect the distance of the throw. I think potential energy and kinetic energy have something to do with this. I will use different weighted objects and measure how far it flings. I think that the heavier the object the shorter the distance. (view Lego racers for information on the energies)
"When military designers tweaked the point of the axle on the lever arm and raised the axle high above the ground, they built their first working trebuchet."(1) The Trebuchet was originally used to destroy enemy walls.It was so the enemy archers didn't get them. They could shoot longer than the archers. It was a time of chaos in medieval times.
How it Works
First you load your ammo pouch. Next you cut the rope thats holding it in place. Then the counterweight would fling the ammo. Finally when the end of your ammo pouch slips free it will go into place and the ammo will go flying. Here is the data from my experiment.
Names of Objects
How Far it Went
I used a 80 g. counterweight.
It turned out as I expected. Everything but the lightest object behaved as I expected. The lightest flew shorter than the second lightest. Maybe it was because it had no wind resistance.