Friday, October 29, 2010

Projectile Launcher- Marbles!

We created a projectile launcher out of an 8x3 inch piece of wood, PVC pipe, an end cap, spring, marble, tape and nut and ramrod. We created a trial to see how different angles affected the distance. Each angle was different and our data was never very consistent. It was interesting to see that the marble would launch in different spots and it was a good lab. It was beneficial and fun!

Thursday, October 21, 2010

Trebuchet Fun For Everyone!!

Our next project in physics was building a trebuchet. A trebuchet is a medieval catapult for throwing heavy stones through walls when in battle. Some believe the trebuchet was developed from the stave sling, which was a powerful sling that was used for mass bombardment. The trebuchet was first introduced to England in 1216 during the Siege of Dover. Louis the Dauphin took the trebuchet across the Channel and attacked the Dover Castle walls successfully. Master James of St. George, who was Edward I's chief engineer, built the Warwolf which is considered to be one of the most powerful and famous trebuchets in the world.

We built our trebuchets and hoped things would work out well when we experimented with them. We tested ours out the night before and the trebuchet was launching straight up so we added more weight. Once we added the weight, the trebuchet began to launch forward. We had about 75 lbs. on the trebuchet and decided to hope for the best when we tested on Monday. Monday in class, we added more weight but when we launched it, the object would only go about 20 or 25 feet each time. The added weight wasn't making much of a difference. Then, when we were about to launch again, we looked and we realized the weights were grazing against the ground. The weights were causing friction against the ground and it was keeping the objects from going 50 feet when we would launch. By the time we realized this, it was the end of the period so we decided to bring a cinder block the next day. Tuesday in class, we put the weights on the cinder block. This made it easier to tie the weights higher and tighter. Finally, after a couple tries on Tuesday, our pumpkin went about 47 feet!! We were all very excited because we accomplished our goal for the trebuchet!  

I learned that friction was affecting our trebuchet from going the 50 feet. Also gravity pulls the weights to the ground when the arm is released. The arm creates an arc that travels when the object travels through the air. Velocity is another part of physics that played a role in the trebuchet. The distance that the object traveled and the speed it was traveling through the air.

I thought the trebuchets were fun and definitely worth doing. It is fun to watch how each group's trebuchet is going to do. All of them were extremely different and we all used different techniques to build them. The launching of the trebuchets went forward, backward, or didn't leave the sling. All were different and I liked seeing all of our reactions when each trebuchet was launched. I think building trebuchets should be done next year, but I think we should have a little more time. We had time to build them, but we were also working on our rockets while we needed to be thinking about building a trebuchet as well. All in all, I thought the trebuchets were fun and I loved seeing all of our reactions and excitement when we launched them!!

Saturday, October 16, 2010


So Mr. Shircliff,
I would like to tell you I just spent 2 hours trying to get my pictures of my bottle and model rocket to upload to my slideshow. However, they would not uplad! So I can show you my pictures or print off pictures but the computer wont let me upload them. So just letting you know that I tried for a very long time and I am very frustrated at this point!! :/ Thank you and I will talk to you on Monday.
Becca Haag

Rocket Slideshow!

Wednesday, October 13, 2010

Rocket Research Paper

Throughout this year so far, we have made many different hands-on projects. We have built mousetrap cars, mini trebuchets and now rockets. Each time we build something,we learn a bit more. The mousetrap cars were most difficult for me and the mini trebuchets were tough because the object we would try to launch would not release off the paper or would not go where we wanted it to. I really have enjoyed the rockets though! I think the rockets have been fun to build and when we would launch them, its entertaining and interesting to see where they will go. It's also fun because we could launch the rockets in different locations and every rocket was different. Some would go high, some low and a few would just explode or disappear and we couldn't find them! The rocket project has definitely been my favorite so far and learning how different materials will affect the rockets height and location makes it very interesting to learn more and experiment.

Rockets have a long, extensive history. They were first introduced in 1232 AD as a fire arrow. Rockets were first used just as weapons. Then in the 20th century, larger rockets began to evolve. It is said that everything up to the 20th century were just simple rockets and mainly used for weapons. However, Claude Ruggieri, apparently rocketed small animals into space as early as 1806. About 15 years after that, sailors hunted whales with rocket-propelled harpoons. Rockets were slowly evolving but were clearly becoming very important.   

There are four forces involved in rocket launching: weight, thrust, and the aerodynamic forces: lift and drag. The motion of an object in response to an external force was described by Sir Isaac Newton. Magnitude and direction are necessary in describing the action of a force. The weight of a rocket is directed toward the center of the earth, also known as the center of gravity. The thrust also acts on the center of gravity, but it depends on the pressure of the exit of the nozzle. The aerodynamic forces are very important for model rockets. They depend on the size, shape and velocity of the rocket, and also the surroundings of where the rocket is being launched. Aerodynamic forces act through the center of pressure. All four forces are constantly changing. What the rocket does,depends on the magnitude and direction of the forces. The final motion of the rocket is described by Newton's Law of motion.

In physics, we built two different rockets. One of the rockets we built from a kit and the other was a bottle rocket. The bottle rockets, we made quicker and they did not go as high. We also had more freedom in building the bottle rockets. There were no instructions or specific materials to use. The bottle rocket I made had styrofoam plates for the wings and I think the wind acted on those when I tried to launch it. We put water into the bottle rockets and launched them with water and compressed air. The weight of the rocket helped us to determine if the rocket would get off of the launch pad. We filled most of the rockets about halfway with water, but we tried some filled to the top OR with no water at all. The rocket filled to the top with water barely made it off the launch pad because it was so heavy, and the rocket with no water made a loud popping noise and flew of the launch pad and high into the air and crashed down.

The other rocket we built was made with a kit. This rocket went higher then I had thought it would. When I would release the rocket, the nozzel was supposed to come out of the body of the rocket, but it never released. I tried loosening the nozzel but it would still never release. Also, every time I launched the rocket, two of my wings would fall off, so I would reattach them with glue so it would be ready to launch the next day. My rocket still went very high and everything else worked perfectly! I really enjoyed the rocket projects we did! I realized that there are different forces acting on each rocket and that each force determines how the rocket is going to move. The building and experimenting of rockets deals with physics, Newton and forces. It was a creative, fun and informative assignment and I think the whole class really enjoyed the rocket project.