PROJECT DESCRIPTION
We had to design and build a trebuchet in groups and try to make a projectile fly as far as possible. The catapult could not measure more than 1 meter in any direction and had to be reusable. It had to be portable and contain a lever arm with a load and effort end.
PROOF OF EFFICACY
Our trebuchet’s base is 7.5 cm wide, 61 cm long, and 3 cm thick. The legs that hold up the axle are 47.5 cm tall and are 5 cm wide, while one is 2 cm thick and the other is 3 cm thick. The lever arm is 0.5 cm thick, 60 cm long, and 3 cm wide. The axle is round and is 31 cm long. There are 4 holes drilled into each of the legs and are parallel to each other. There are 3 of the same holes drilled into the lever arm. Each of the holes was drilled with a 5/16 inch (0.79 cm) drill bit. The projectile we had used is a 7 gram clay ball with a 40 cm string to keep it attached to the lever arm.
The holes we drilled were a bit too small, so we moved the same drill bit around to somewhat expand the size.
We originally had 3 holes in the lever arm, but changed where we put them after seeing that we wanted data from a different position, we wanted one in the middle so that we would get the ratio we wanted.
We used a 2:1 ratio for the lever arm because it would make the ball go farther compared to an arm with a 1:1 ratio.
Our lever arm was the lightest we could find and was easier to move than a heavier arm.
We used a rubber band with a greater spring constant to help release/launch the mass.
We decided to focus on the mass of the projectile to find what flew furthest.
CLEAR PARAGRAPH
Out of a 14.6 gram mass, a 7 gram mass, and a 0.8 gram mass, the 7 gram mass travels the farthest. We took the three masses and then launched them with a catapult to see which would go farthest. In the first trial, the 14.6 gram mass went to 8 meters, the 7 gram mass went 22 meters, and the 0.8 gram mass went 9 meters. During the second trial, the heaviest mass went 13.5 meters, while the medium mass went 13 meters, and the smallest mass went 15.5 meters. In the final trial, the 14.6 gram mass traveled 12.5 meters, the 7 gram mass traveled 19 meters, and the 0.8 gram mass traveled 9 meters.
Air resistance took effect on the smallest mass, while inertia impacted the largest mass, therefore letting the 7 gram mass travel furthest. Air resistance caused the smallest mass to stray from its course, while inertia made the largest mass more difficult to move.
The horizontal velocity of the trebuchet was 16.42 meters per second (0.01 miles per second) and the vertical velocity was 13.72 meters per second (0.008 miles per hour). The kinetic energy was 1.108 Joules and the potential energy was 1.711 Joules.
REFLECTION
It was fun to work in groups of our choice, although we got off topic at times. One other groupmate and I had been in the same group previously and had to go back and finish our last project, which we had left incomplete. We had less of an experience with this project because we had to take time away so that our Physics of Sports Video could be turned in. Since the length of this project was so short, we missed a lot of it and had to catch up later.
I worked on this project with Alexis Bishop and Brittany Fung.
We had to design and build a trebuchet in groups and try to make a projectile fly as far as possible. The catapult could not measure more than 1 meter in any direction and had to be reusable. It had to be portable and contain a lever arm with a load and effort end.
PROOF OF EFFICACY
Our trebuchet’s base is 7.5 cm wide, 61 cm long, and 3 cm thick. The legs that hold up the axle are 47.5 cm tall and are 5 cm wide, while one is 2 cm thick and the other is 3 cm thick. The lever arm is 0.5 cm thick, 60 cm long, and 3 cm wide. The axle is round and is 31 cm long. There are 4 holes drilled into each of the legs and are parallel to each other. There are 3 of the same holes drilled into the lever arm. Each of the holes was drilled with a 5/16 inch (0.79 cm) drill bit. The projectile we had used is a 7 gram clay ball with a 40 cm string to keep it attached to the lever arm.
The holes we drilled were a bit too small, so we moved the same drill bit around to somewhat expand the size.
We originally had 3 holes in the lever arm, but changed where we put them after seeing that we wanted data from a different position, we wanted one in the middle so that we would get the ratio we wanted.
We used a 2:1 ratio for the lever arm because it would make the ball go farther compared to an arm with a 1:1 ratio.
Our lever arm was the lightest we could find and was easier to move than a heavier arm.
We used a rubber band with a greater spring constant to help release/launch the mass.
We decided to focus on the mass of the projectile to find what flew furthest.
CLEAR PARAGRAPH
Out of a 14.6 gram mass, a 7 gram mass, and a 0.8 gram mass, the 7 gram mass travels the farthest. We took the three masses and then launched them with a catapult to see which would go farthest. In the first trial, the 14.6 gram mass went to 8 meters, the 7 gram mass went 22 meters, and the 0.8 gram mass went 9 meters. During the second trial, the heaviest mass went 13.5 meters, while the medium mass went 13 meters, and the smallest mass went 15.5 meters. In the final trial, the 14.6 gram mass traveled 12.5 meters, the 7 gram mass traveled 19 meters, and the 0.8 gram mass traveled 9 meters.
Air resistance took effect on the smallest mass, while inertia impacted the largest mass, therefore letting the 7 gram mass travel furthest. Air resistance caused the smallest mass to stray from its course, while inertia made the largest mass more difficult to move.
The horizontal velocity of the trebuchet was 16.42 meters per second (0.01 miles per second) and the vertical velocity was 13.72 meters per second (0.008 miles per hour). The kinetic energy was 1.108 Joules and the potential energy was 1.711 Joules.
REFLECTION
It was fun to work in groups of our choice, although we got off topic at times. One other groupmate and I had been in the same group previously and had to go back and finish our last project, which we had left incomplete. We had less of an experience with this project because we had to take time away so that our Physics of Sports Video could be turned in. Since the length of this project was so short, we missed a lot of it and had to catch up later.
I worked on this project with Alexis Bishop and Brittany Fung.