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etracey99 last won the day on January 29 2018

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  1. Team Name: KT Explorations Inc. Available Funds: $100,000 Vehicle Name: The Speedy Boi Vehicle Parts List and Cost: 1. MK16 Parachute $422 2. MK1 Command Pod $600 3. FL_T100 Fuel Tank $150 4. LV909 Terrier LFE $390 5. TR18 Stack Decoupler x2 $800 6. FL_T400 Fuel Tanks x3 $1500 7. LV_T45 Swivel LFE $1200 8. 1.25 m Heat Shield $300 9. AVTR8 Winglets x2 $1000 10. RT_10 Hammer SLB x2 $800 11. Aerodynamic Nose Cones x2 $480 12. TT_38K Radial Decoupler x2 $1200 Total: $8842*(10% Foreign Enterprise Tax) = $9,726.2 Design Goals: Our vehicle is designed to launch off of Planet Kerbin and achieve a steady orbit of a little over 70,000 meters over the surface of the planet. Launch Goal: We are hoping to learn the requirements of making it out of the atmosphere and create a steady orbit so we may be able to escape Kerbin from there at later times. We expect to get the "Stable Manned Orbit," "Stable Orbit," "Manned Launch to 50 km," "Manned Launch to 10 km," and "Launch to 10 km," milestones. Pilot Plan: The pilot will be flying to 100 m/s and start to tilt due East. The pilot will then work his/her way to a 45 degree ascent with respect to the ground around 15,000 m above the surface of Kerbin. From there, the pilot will burn until the apoapsis reaches 70,000 m above Kerbin and will cut the burn. When the pilot is close to apoapsis, he/she will burn at the prograde until the orbit is around the entire planet and the periapsis is a little above 70,000 m. They will then reach the final stage of the rocket and return to Kerbin by burning at retrograde around the time the pilot reaches the periapsis, and will parachute to the ground!
  2. I don't know if I would go as far to say the greatest game of all time, but still pretty good! Nice to tie some physics into a classic series!
  3. Many of us know the Aurora Borealis as the 'Northern Lights'. This natural phenomenon is, of course, thanks to the physics of our Earth and its atmosphere! (Photo credit: NASA) The Aurora Borealis is an extremely beautiful event that occurs most often close to the magnetic poles of Earth. It occurs due to charged particles coming from the Sun of which collide with other molecules found in the Earth's atmosphere. Solar winds from the Sun carry these charged particles and when the wind passes by Earth, particles may be trapped in the atmosphere from the Earth's magnetic fields! The charged particles ionize molecules in the atmosphere, which give off light. This creates the Aurora Borealis! I had previously thought that the Northern Lights were from light reflecting somehow, but it awesome to see that it is caused by magnetism, which fits into our past few units very nicely.
  4. Have you ever seen a hot air balloon? Personally, I find them terrifying, but I always see a few every year while I'm enjoying time at my cottage on Keuka Lake. Well, it turns out that hot air balloons actually float through the air due to buoyancy, which we generally associate with water. This is based on Archimedes' principle, which says that an object of any shape that is suspended in a fluid is acted on by an opposite force equal to the weight of the fluid displaced by the said object. So a hot air balloon floats in the air using the same idea as an object that floats in water. In a hot air balloon, the buoyant force is generated by heating the air inside of the balloon, which makes the air less dense than the cooler air around it. This creates a buoyant force and lifts the hot air balloon into the sky as if it were an object less dense than water floating at and above the surface. What is even cooler is that the balloon has enough hot air in it to create enough lift to carry the gondola and the passengers riding along!! Cool!
  5. We live in a world where we are constantly trying to better our technology to be greater and more efficient. What if I told you that we achieved the most efficient mode of transportation of all time already? And what if I told you that this transportation was developed as far back as 1817? Behold! The bicycle. Since the first bicycle coming from Germany in 1817 (called the running machine), there have been great advancements in bicycles: Although this invention has been around for about 200 years, the bicycle proves to be one of the greatest and most efficient inventions in transportation. This is simply because bicycles are able to convert 90% of the energy that a human can put into it by pedaling directly into kinetic energy that powers you along. This is over 4x better than the conventional gasoline engine we use in most cars, which clocks in at only being 20% efficient with its fuel. In other words, if people could somehow use gasoline as energy in their bodies and ride a bike, it would be a 4x more efficient use of the same amount of gasoline when used in a normal automobile. So keep that in mind next time you want to go out to get ice cream or visit your friend down the road, a bike is a more efficient machine and it is environmentally friendly!
  6. Today, the internal combustion engine is a very important part of the average person's life. We experience the wonder of this engine in most automobiles that use gasoline as a fuel. As one could guess, the Internal Combustion Engine is an engine in which combustion occurs internally... just kidding! (oversimplification at its finest). In all seriousness, let us discuss the four-stroke internal combustion engine since it is not too difficult to understand! It is called a four-stroke engine because there are four 'strokes' per combustion cycle (up, down, up, down). It goes like this: The first stroke is for the intake. The intake valve opens as the piston goes into its down position and lets in an oxygen-gasoline mixture (known as the fuel-air mixture). Going back to another post I wrote, the fuel-air mixture can be tuned for better gas mileage and/or power! The second stroke is to compress the fuel-air mixture in the combustion chamber. While the piston is on its way up, the intake valve quickly shuts and an airtight situation is created, which allows for the compression. The third stroke, or the combustion stroke, occurs directly as the piston is reaching the top of the chamber. The fuel-air mixture, in its extremely compressed state, is extremely flammable and when the spark plug goes off, explodes! This creates a great force and shoots the piston down. The fourth and final stroke is to push the exhaust out. As the piston is on its way back up, the exhaust valve is opened, and the air that is created after the explosion is let out so fresh air can be let in. After this, the cycle repeats itself! I found a diagram from keveney.com that I believe will help to imagine what it all means: This process is the origin of how your car actually moves! The combustion pushes the pistons, which turn the crankshaft, which turns gears in the transmission, which turns the drive shaft, which turns the differential, which turns the axles which turns your wheels! A lot of steps, but very useful to know!
  7. Some common sense physics is that in most cases, things roll better than they slide. For example, roller blades work a lot better on asphalt than a pair of snow skis do. This is because there is a lot of friction created with sliding, but when something can roll over the ground, the friction is greatly reduced. A ball bearing is a device that 'bears' a load and rolls over smoothly. This is done by having round objects enclosed in a smooth inner and outer shell. There are several types of bearings in existence, but let us discuss ball bearings since they are the most common type of bearing and we have all most likely experienced. Ball bearings are best known for being in skateboards, longboards, roller blades and even bikes. The round objects that ball bearings use are, (you guessed it) balls! This is cool since the balls only touch the inside and outer smooth shells a very small amount. This creates a very small amount of friction, which results in wheels that can spin a very long time! Often times, longboarders search for the best and most efficient ball bearings so their rides are smooth and do not require a lot of pushing. Here is a diagram of a ball bearing: A little animation of a ball bearing, see how the balls rotate and let the outer shell move: And finally, some ball bearing action!:
  8. This is a kangaroo: Kangaroos are large marsupials that have an iconic talent for jumping extremely far due to their well developed musculoskeletal system. How far can they jump? On a flat strip of land, a kangaroo can jump approx. 9 meters far and about 3 meters high. This is almost 30' long and 9'10" high! That is truly amazing! How do they do it? The musculoskeletal system of kangaroos are extremely efficient and is made for jumping far and quickly! The kangaroo is able to store potential energy in their legs every time they land, and this potential energy assists them in jumping. Imagine a living spring; the spring could use the energy it has stored up through life processes to jump high, but if it compresses itself to build up potential energy, it can exert that energy in addition to the energy it would normally use. This results in a very high and far jump! 832 × 429 - chegg.com
  9. Have you ever waterskiied? If you have, I'm sure that you would agree that it is very fun and thrilling! I have been waterskiing for about 9 years, and I have always been fascinated by how it works. When I was taught to waterski when I was 9, my Dad and Grandpa told me that it was just like getting pulled up out of a chair and standing up. So untl I was older, that is all that it ever was to me. Well, it turns out that the physics behind waterskiing is actually very simple! But first, I will show you how waterskiing is done: (These are pictures of me from 2011) First you sit in the water with the rope in your hand, and your skiis out of the water: Then you let the boat pull you and you gradually stand up and give a little resistance to the skiiis (look at those super big muscles): You continue standing up until you are out of the water until you are nearly straight up, it is important to lean back!: After you're up, you can ski around! I like to go in and out of the wake of the boat so I can go fast and corner quickly! I also enjoy dropping one of the skiis, and I go on only one: Anyway, the physics side of things is not too bad: We know that Newton's Third Law of Motion states that for every action there is an equal and opposite reaction. When the boat is pulling you, you will create an equal and opposite force back. When you lean back, you're countering enough force of the boat so that you do not fall over frontwards, and you will skid along the top of the water. This is all demonstrated in this graphic: Needless to say, waterskiing is a very interesting sport and just like everything, can be explained with a little bit of simple physics! I hope that one day, if you get the chance, that you will try waterskiing since it is so fun!
  10. I've been playing some Forza Horizon 3 on Xbox lately, and I have been having a lot of fun! I personally enjoy racing games a lot and I have been trying to get a little bit of playing in during this spring break. Something I have never done in another game, however, that I can do in Forza Horizon, is tune my cars. Just like musicians tune their instruments, many avid drivers often tune their cars to run exactly how they want them to. For example, you could tune your car's shift points so the car shifts into the next gear at different times, and you could tune the fuel-air mixture to create the perfect situation for your car to have in its combustion chambers. This is all done to increase or perfect the way that the car runs -- to increase acceleration, to increase top speed, to make it easier to drift, the list goes on. Tuning cars has become easier and easier as of late due to the increased level of technology in computers that are in cars. One could tune anything! I was tuning a Lamborghini Countach, and the car I was trying to perfect had both adjustable front and back spoilers. The car was converted to all-wheel drive, so having downforce in the front and back is extremely advantageous so the car's wheels are pushed to the ground as it accelerates, which creates more grip. Furthermore, the downforce in the front is great for cornering, which is especially needed for highspeed racing on a car with reduced weight. All in all, I just wanted to share how a silly video game could simulate such a real situation for cars across the world, and how a little bit of physics could boost the performance of a car extremely well! Lamborghini Countach: Front Spoiler (Black piece at the bottom): Rear Spoiler (on Countach): Rear Spoiler (Custom on Countach in Horizon 3): And Some Physics:
  11. As many of you know, the banana is my favorite fruit. An apple banana* a day keeps the doctor away! Bananas start off by being very short and straight: As time goes on, however, they begin to curve upwards... Due to a process known as negative geotropism, which means that the bananas grow away from the force of gravity! They do this because in the forests, if they started to grow sideways towards the light that penetrates through the trees and plants above them, they would topple over. So bananas figured out that if they grew up towards the light instead of sideways, their plant would not topple over, and they would all be safe. Thank you for existing, bananas.
  12. They are so hard to ride, but it looks so cool when you get it right!
  13. What I thought was going to be the hardest midterm I had this year, actually turned out to be not too bad! For the entire first half of the year, I have now found that practicing physics at the level we have been working on has prepared us very well for the midterm and the AP. As a person who struggled through a lot of the review packet and put in a lot of studying for the weeks leading up to the test, I think it is safe to say that practicing physics and learning it so far this year has been difficult, but rewarding. For the rest of the year, I think that my studies can get even better and efficient, and reviewing the mechanics part of the class will progressively get better and better. For the E&M section, I am going to have to continue pushing through the difficult learning curve and remain confident in myself so when the AP's come around, I am ready to conquer them. Stay confident and be proud!
  14. To many, planes fly because they go fast and they have wings. When I was younger, that is how simple I thought it was. Well, there is a little more to it than that. There are four forces of flight: lift, drag, weight, and thrust, which correspond to upward, backward, downward, and forward forces, respectively. Thrust is what moves the aircraft forward through the air, it overcomes the drag and the weight of the plane. The thrust for a normal plane comes from an engine/propulsion systems such as a propellor, turbine or a rocket. Weight is simply the force on the airplane caused by gravity. Drag is the force that opposes the plane's motion through the air and is generated on every part of the airplane. There is even drag that is caused by the generation of lift called induced drag. Lift is a very complicated force. It is the force that is the opposite of the plane's weight and it holds the plane in the air. Some lift is generated all over the entire plane, but a majority of it is generated on the airplane's wings. This is what we will discuss a little further, because lift is extremely interesting: How is lift generated? Lift occurs when there is a flow of a fluid turned by a solid. A fluid can actually be catorgorized as either a liquid or gas, so when lift occurs, the plane and its wings turn the air. The wings are designed so that a low pressure area is developed with air that moves very quickly along the top of the solid, and a high pressure area is developed with air that moves more slowly along the bottom of the solid. The result is an upward movement as the high pressure pushes the plane into low pressure with an equal, opposite force. Needless to say, planes have incredibly well designed wings that create lift, which is the vital part to why planes fly, and is very awesome to see the physics behind!
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