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.
The most compelling part of this project was when the parachute deployed. I wasn’t sure if the parachute would deploy or not. Before I launched the rocket, I made sure to put the parachute loosely in the nose cone so when the nose cone came off, the parachute wouldn’t be stuck in it. As the rocket launched, I was very excited!
First the energy of conservation. The setting of the trebuchet before firing is shown in Fig 1. A heavy counterweight of mass (M) (contained in a large bucket) on the end of the short arm of a sturdy beam was raised to some height while a smaller mass (m) (the projectile), was positioned on the end of the longer arm near or on the ground. In practice the projectile was usually placed in a leather sling attached to the end of the longer arm. However for simplicity, we shall ignore the sling and compensate for this omission by increasing the assumed length of the beam on the projectile’s side. The counterweight was then allowed to fall so that the longer arm swung upward, the sling following, and the projectile was ultimately thrown from its container at some point near the top of the arc. The far end of the sling was attached to the arm by a rope in such a way that the release occurred at a launching angle near the optimum value ( most likely by repeated trials) for the launch height. The launching position is shown in fig.2 where we have assumed that the projectile is released at the moment the entire beam is vertical. In the figures: (a)=height of the pivot, (b)= length of the short arm, (c)= length of the long arm, while (v) and (V) are the velocities of (m) and (M), respectively, at the moment of launching.
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.
Standing some 3 feet tall, this trebuchet could repeatedly launch a 2-3oz object in excess of 20 feet.
The sling will be 18 inches, or the length of the longer end of the arm. I will use a metal pivot point, in order to keep stable and support the weight of the counterweight. The counterweight will be 4985 grams(13 pounds), or approximately 133 times heavier than the payload, which is 45 grams, as according to Siano’s optimal factors of the Trebuchet. The sling will be a string, fully attached on one side, but only a loop around a rod to be released at the optimal release location of 45 degrees to the vertical. Also, the pivot point will be elevated to a height of 1.5 feet, with a sling that is 1.5 feet long. The weight of the arm is projected to be 0.5 pounds, in order to maximize the distance of flight for the golf
speed of the ball rolling down a ramp. From the data that I'm going to
8. Tie an arm-length piece of string through each of the holes punched in the corners. Tie their open ends together.
These simple devices either used torsion, which uses wound rope to secure the arm, or traction, or manpower. Using gears and locks to build theirs, the trebuchet differs in it use of simple wood and rock projectiles. The Romans and Greeks versions were extremely difficult to calibrate and reproduce. It is believed that the first traction trebuchet had been primarily constructed in China around 300 B.C, developed after the stave sling. A stave sling is basically a sling shot; it is a small device that has the ability to launch small, blunt pieces of rock or clay from a pouch centered between two equal lengths of cord. It is also known as the shepard sling. While in China, the trebuchet is said to have been able to be shot between the strength of two men, or from the mighty power of two hundred and twenty-five pulling a stone that weighed almost one hundred and fifty pounds; the giant rock was thrown more than eighty yards across the battle field. After the traction trebuchet had risen in China, Arab and Islamic traders began to spread awareness of the new artillery, causing more cultures to accept it and therefore use it within their own fights. It was especially important and strengthening to the Arab and Byzantine armies throughout the eleventh and twelfth centuries. As more eyes settled onto the wooden weapon, limitations of the device were brought to the light. These restrictions,
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
I, Kylie Innes, have chosen to do the trebuchet as my science demo. The trebuchet is a medieval siege engine that was used to throw projectiles at the enemy. I have an interest in weapons, so the trebuchet was a perfect fit because I was interested and excited about doing the project, rather than it be boring for me to do. I chose to work alone for this project. One reason for working alone is because I work better by myself than in a group for projects. Also, I am a very busy person, so it would have been a challenge to meet with my partner to work on the project.
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.
Do I think that catapults will help me in my line of work? No. I don’t think they will because what I plan to do has nothing to with launching things from a machine. What I plan to do is work with other people and use very little electricity.
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.
...arrow to reach optimal height and back down. Once I got the value of the gravity, I found that it would be helpful in figuring out the time (t) that it takes the arrow to reach its optimal height and back down to the ground. The equation I used to figure this out was v=u+a(t), v being the final velocity, u being the initial velocity, and a being the acceleration. I then replaced a(t) with g(t) since gravity (g) is a constant value. I did this because gravity has no effect on horizontal velocity, but speeds and slows down the vertical velocity. The regular equations for acceleration in both horizontal and vertical velocities are ax=0 and ax=-g. So I decided that I would use a 45° angle as my reference angle, since it achieves the greatest range.
In this assessment of the projectile motion of an object, I found that it can be applied to many useful situations in our daily lives. There are many different equations and theorems to apply to an object in motion to either find the path of motion, the displacement, velocity, acceleration, and time of the object in the air.