Application Physics #3

Projectile Motion 

    A projectile motion is an object upon which the only force acting is gravity, in this case the payload is a projectile, due to the fact that once the force is acted upon it then it will be air bound therefore the only force acting on it would be gravity. The only thing acting on the water balloon, or any payload, is its inertia and gravity, therefore Newton’s first and second law come into play. Some variables that exist for projectile motion are air resistance, projectile speed, projectile angle and gravity. The air resistance would move against the projectile the amount of air resistance is determined through the mass of the object and other factors, in this example it could be the wind. Another variable is the projectile angle of the projection, the path that the object takes is usually determined by what angle it was launched at, usually 45 degree angles work the best because it is not to high or low. The projectile speed would be the amount of velocity the object has, if it is high then it will go further. Gravity is what ultimately pulls the path of the projectile closer and closer to the ground, without it it would go on indefinitely. 

    A way to modify the projectile motion is by decreasing the air resistance by performing launch in a windless room with little outside forces other than the ones already present. The other modification would be the projectile angle, if the angle is set to launch at 45 degrees than there projectile will reach maximum distance from the catapult.

Application of Physics #2

Forces  

      Centripetal force is the force that acts on an object moving in a circular path and is directed toward the center around which the body is moving. The arm rotates in that circular motion when the counterweight drops and the sling rotate around end of the shorter arm. This force will increase the acceleration of the object being flung. Also another force that is working on the catapult is gravitational force on the counterweight, the counterweight falls due to gravity, if it were not there than the arm would not rotate and the balloon would not be slung. Also there are a couple forces acting upon the arm of the trebuchet, the counterweight and the mass of the balloon. The distance of where the rod that holds the arm up rotates will affect the force of the trebuchet. This means that the angle of the rod compared to the arm matters.

   A way to modify the centripetal force is by elongating the sling by increasing the distance it travels around the shorter arm. Another modification is to change the gravitational force by increasing the mass of the counterweight, which will in turn increase the acceleration of the balloon. To modify those forces acting upon the trebuchet one would place the rod in a 0-90 degree angle.

Application of Physics

Energy 

    Potential energy exists in the heavy balloon (a.k.a. payload) that is usually elevated; potential energy is an object can store energy as the result of its position. Therefore the counterweight is the object that has the most potential energy relative to its position compared with the rest of the catapult. The kinetic energy that exists in the trebuchet catapult is in the payload, or in other words the projectile of the object. Kinetic energy is the energy of motion and in this case the rotational motion of the sling, the arm and the payload. Essentially the potential energy of a counterweight is converted to the kinetic energy of the projectile as one side of the arm drops and the other is lifted.

   Two ways to modify/ increase potential energy is by increasing the distance between the object and the ground or adding mass to the object. It is known that the best ratio between the payload and the counter weight is 1:100, therefore the heavier the counterweight the more potential energy the counterweight has. In this case the group is trying to get the counterweight as close as possible to this ratio. For kinetic energy the increase in mass will also help increase the energy, in this example the balloon would have a higher kinetic energy if it increased in mass, also the velocity of the kinetic energy. A modification would be that the velocity of the kinetic energy of the arm increased then the kinetic energy in the arm would also increase

Getting down to business

5/12/14
Met for the last time at Maria's house to finalize the project. Took less time than we expected.
https://twitter.com/CatapultProjec1

Victory at it's finest. (Josh refused to be in this picture so he just took it instead)

TRIAL #3

This was our 3rd and final trial. In this trial we replaced the wooden stick with a metal one that Maria's dad had in their garage. We also fixed the end hook to be precisely on the top of the arm rather than on the bottom of it. We figured that this was more successful. The last thing we did was try it out with 3 pavers instead of 4 and found to be a bit more successful. This was our victory trial.  

TRIAL #2

This was our second trial, this time we tried using a bucket with 4 pavers rather than a bucket full of water. Unfortunately, you can see & hear in this video that the stick holding the arm of our catapult snapped because the 4 pavers were too heavy. Not a successful trial.

5/12/14
Met in the computer one last time to wrap up last minute details to add to our blog, catapult, & to record our final trial before we go & launch.

4/30/14
Meeting up a day after our power tools ran out of battery. This time we met up at Maria's house with a little bit more luck. We got the whole catapult built & put it together. At first we didn't know how to attach the support of the catapult but then Maria's dad got home and suggested we cut the wood with the saw to then attach it. We also ran a couple trials, which we weren't so successful with.

We all got a chance to cut some wood with the powerful saw, it was kind of scary when Maria almost cut her finger because she was holding the wood down from the wrong side. ALMOST had to make a stop at the new Oviedo ER. 

This is part of our catapult without the trigger mechanism. Not the finished product. 

Josh is frustrated.

TRIAL #1

     Frustration at it's finest. We didn't know what else to do to make the water football project further. We originally started using water in the bucket to see if that would help but there was only so much water we could pour into the bucket and every time we went to launch, it was just a messy pool party.  We then decided to start using a different bucket because the blue bucket in the picture was a bit wide for the width we had built the catapult with. And during every launch the bucket would not fully let the weight down because the width of the catapult was too small for the bucket to easily slide through. We also decided to start using left over pavers that were around Maria's house because we thought that adding & taking away weight would be easier. 

Bump in the road

4/29/14
Whole group is here, figuring out what to do with this catapult. We actually got to build part of the catapult. The sides of the catapult are finished... we just had technical difficulties with the power tools because some ran out of battery, so until next time.

Trying to start things

5/6/14
Whole group met together, had some technical difficulties with the supplies we needed to you and actually finding supplies. Got the idea of what it was we needed to do but we needed to cut the meeting short because we couldn't start building the actual catapult.

Our newest addition to the group. We will be launching her instead of the water balloon.

Josh finding inner peace after he found out Maria was the one who was driving to Home Depot.

Trying to find scraps of wood but we were a tad late to the party.

After walking around Home Depot for an hour we finally got all our supplies with the help of our friend, Jose. He helped us get the 70% off wood (the scraps) and gave us tips to build the catapult. We ended up getting the left over scraps of long wood, with a couple of hooks to try our trigger mechanism, we also found the bucket, pavers, and rope around our houses. Successful day.

Getting started

4/17/14
In the computer lab with the group doing research for the catapult. Trying to figure out what it is we have to do to design and build the actual catapult.