The Ratapult
Objective:
My objective in this project was to produce a rat-trap powered catapult. It has a base of 30 cm by 30 cm, and has a theme of cows trying to escape the farm. The reason they want to escape is because they are being killed and turned into steaks, against there will. That is why I developed this ratapult, to save the cows. The cows also wanted me to ask you to eat more chicken.
Hypothesis and Drawing:
I hypothesize that if I build the ratapult to a 25-degree angle, and release the hacky sack at a height of .55m then there will be enough velocity to project the hacky sack exactly four meters. The ratapult will release the hacky sack with an initial velocity of 5.8 m/s, and as a result the hacky sack will travel 4.0 meters in .75 seconds.
Procedure:
The first step I took was to paint all of the wood white. After that I put wallpaper on the board that I am going to nail the rat trap to. I then attached the measuring cup to the rat trap by drilling a hole in the middle of the measuring cup and then using string to attach the cup at both the drilled hole, and the hole at the bottom. Then I nailed the rat trap into the board with wallpaper. That board was then nailed into the base.
Then I attached the “steps” to the milk crate. The steps will hold the base of the ratapult at a 25-degree angle. I attached the “steps” by drilling holes in the bottom of them and then tying them to the milk crate. Then I nailed the board with wallpaper into the back end of the base. The base was then nailed into the “steps”, and glued grass decorations and cardboard cows to the base. The ratapult was completed.
Data & Observations:
I found the initial velocity, or Vi, by finding the horizontal velocity, or Vx, and then using the equation Vx = Vi * cos(angle).
The angle was 25 degrees, so I input that into the equation also. That made the equation look like
5.3 m/s = Vi * cos(25)
I divided both sides by sin(25), then that gave me an initial velocity of 5.8 m/s.
Then I decided to find the Vertical height of the hacky sack, so I used the equation
Vy = Vi * sin(angle). Vy stands for initial vertical velocity.
For almost as long as civilizations began they have been fighting against each other. Often times these wars come down to who has the better military equipment. When one army creates an elite war machine another army is sure to soon copy or improve it. For example the U.S. Army Signal Corps purchased the first ever military aircraft in 1902 (Taylor). Two years later the Italians were also using aircrafts. The trebuchet catapult is no exception; it was one of the most destructive military machines of its time (Chevedden, 2000). A trebuchet works by using the energy of a falling counterweight to launch a projectile (Trebuchet). In this research paper I intend to explain the history and dynamics of a trebuchet catapult.
The Trebuchet was created by the Chinese in 300 BC and was known to be the most powerful of all the catapults. The Trebuchet was made of a long arm possibly up to 60 feet long, which balanced on a fulcrum, which was far from the center. A counterbalance, which is a heavy lead weight or a pivoting ballist box filled with earth, was attached to the short arm. A sling was attached to the end of the long arm and a rope was attached to the long arm, which was pulled down until the counterbalance reached its maximum height. The sling was loaded with projectiles as the rope was released and the counterbalance drops down. The potential energy is converted into kinetic energy and when the long arm is brought to an abrupt stop the projectile continue with the velocity produced by the kinetic energy
The Purpose of this lab is to use the impulse and momentum concepts to explain what happens when the eggs are dropped onto various objects.
Catapults are devices used to launch items far distances. One type of catapult that uses a sling and weight to fly items is called a trebuchet. Trebuchets were heavily used in the Medieval Ages as weapons to fling stones toward enemies. A diagram of a trebuchet is shown in Figure I.
Carmichael, Ralph. "Numerical Procedure for Computing the Trajectory of a Baseball." 2003. 16 Nov. 2004 .
So using this formula but with the data we collected from our first attempt, this is what it would look like; Tan(60°) x 23m = 39m. As you can tell this answer collected from our first attempt is very well incorrect, but at the time, our group did not know this.
8. Tie an arm-length piece of string through each of the holes punched in the corners. Tie their open ends together.
Hurling an object towards one’s enemy may seem as old as time itself. People have hurled fists at each other, thrown spears, and launched giant rocks into enemy territory. The use of catapults, and other objects that hurl projectiles, also seem as old as human civilization itself. The effectiveness of the catapult in flinging objects over a great distance and causing destruction is due to a few basic physics principals that govern force, energy, motion, speed and mass to name a few. The design of the catapult denotes a change in modern warfare to the engineer behind weapons being just as important as the actual soldiers and people who use them.
With the arrival of fortifications such as forts, strongholds and gigantic walls to protect cities from hostile forces, conquering cities became so difficult and costly to do that every civilization must come up with an ingenious way to overcome this problem. Out of all methods ranging from complex engineering feats such as the siege tower to simple methods such as employing ladders, none are as well-known or as old as the catapult.
For our final project in physics we were assigned to create a moving car out of a mousetrap. In order to do that, the three of us had to work together and collect our thoughts to create a car that moves a certain length. We built a car using the following materials: mousetrap, 4 CDs, zip ties, BBQ skewers, straw, wire cutters, ruler, x-acto blade, scissors, cardboard, pencil and foam. Our first step in this experiment was deciding on what we needed to get and what we already had. Most of the list was stuff that we had in the classroom and we only needed to bring a few things from home. In the end we didn’t spend any money. We use a youtube video (https://www.youtube.com/watch?v=mVNFxlEMWvw&feature=youtu.be) as a refrence for building the
Also, more incent topic in history of the catapult was believed to have opened in 12th century France with the inventions of the trebuchet. This huge train of siege is stated to have hit good fear in the hearts of the opponents. The project and this pure power have hurled this example catapult history through the history.
I am going to tell you about the planning and result of my egg drop project. First I took a green container and surrounded the outside with clear duct tape. Secondly I taped the inside which was very tricky. I then put bubble wrap in and taped the egg to it. I taped the top so the egg couldn’t fall out. I named the egg Aidan and have drawn a face on it.
Wright, Tim. "How Things Work: Electromagnetic Catapults." Editorial. Air & Space Magazine Jan. 2007: n. pag. Airspacemag.com. Air & Space Smithsonian. Web. 10 Nov. 2013. .
In doing this, let us consider that freely falling objects moves in a vertical direction that is, along the y-axis. instead of using Δx, we will use Δy.
Here, we can use the vectors to use the Pythagorean Theorem, a2 + b2 = c2, to find the speed and angle of the object, which was used in previous equations.