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About Shadoof

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  1. I recently saw a video of an open MRI machine, I didn't know that there is one magnet that just spins really fast on the inside along with other equipment. It's amazing that it's perfectly balanced so it doesn't tear itself to pieces.
  2. Another crazy creation from Boston Dynamics is the Sand Flea. This little robot has the ability to jump, very high. the 11 pound, or 4.99 kg robot has the ability to jump 30 feet in the air, or 9.14 meters. Using potential energy we can calculate the energy needed to launch the robot. Using mgh we can see that the robot outputs 446.96 Joules of energy for a full height launch. Also assuming that no energy is lost the launch velocity of the bot is about 13 m/s. Boston Dynamics say that the robot can launch about 25 times, giving the total energy within the robot to be about 11174 Joules or about 69837500000000000000000 eV.
  3. Quite recently Boston Dynamics made another cool looking robot that is built with two legs and runs on wheels. In order for this robot to be able to move around without falling over. The ability to not fall over is helped by inertia and the very complex computers within the robot allowing for many calculations to be made in order to put the robots weight in exactly the right spot. What is the most surprising thing about this robot is it's ability to jump completely autonomously. It is able to detect an object in front of it and make the correct calculations to jump the object and safely land on the other side. The way the robot turns and stops also shows how inertia is used, as the robot is stopping it will lean back as to counter act the inertia wanting to send the top of the robot forward. Again as the robot is turning to either side, it leans the direction it wants to go in order to not tip over. Here is a short video demonstrating all of its sensibilities.
  4. As we know through kinematics the period of a pendulum is determined by its length, by increasing the length of the pendulum the time it takes for one cycle gets a little longer. If we line up a bunch of pendulums in a row and just make each string a little longer than the last we can make a very cool looking pendulum wave. Eventually these pendulums will become out of sync and it will look like a mess, but they will follow a pattern and will eventually make the very satisfying wave form once again.
  5. In old times, hunters didn't have guns and cool stuff to help get food. They had to come up with a new and genius way to hunt animals for delicious food. Around 21,000 years ago, some people in the modern day french area came up with the idea of using a lever arm to be able to throw a spear faster, farther, and more accurate. The way in which this device works is that it acts on a lever arm. Since the throwing arm is long more force is applied to the object, effectively multiplying the force put into the spear.
  6. A fantastic game that has an incredible physics physics engine is Kerbal Space Program. At the end of Physics C we do get to play with this game, but I own the game and have had many fun times in it. The premise of the game is you own a space agency on the planet Kerbin (earth). You have to design rockets or planes that can power themselves taking into account of lift and mass of the aircraft. You also have to worry about how the atmosphere will effect the craft including the drag due to air resistance. The game also lets you do gravity assists around any planet, probably using the gravitational force formula. It is a fun game to just mess around in and see how many rockets you can strap to a single capsule. But it can also be very difficult because of the real world physics you have to deal with when trying to land a space craft on the Mun.
  7. I think this actually happens on the international space station, just on a smaller scale. Pretty sure the name for it is Time Dilation.
  8. A recent Youtube video from a channel called Vsauce caught my attention. In the video he mentions this line created by a specific set of geometric events. This line is quite special in its properties, if made into a 3D object it is the fastest path from one point to another. This is due to the perfect balance between distance traveled and velocity. In this video you can see the three different paths that are built, the linear path, the Brachistochrone path, and the 'extreme' path as they call it. The linear path has the least amount of distance traveled, but also at a slower rate then the others. The 'extreme' path has the greatest speed, but also the most distance to travel. And the Brachistochrone path has the perfect mix of speed and distance to travel making it the fastest. Another interesting property of the Brachistochrone curve is that no matter where the ball starts on the path it takes the exact same time to reach the bottom. Here is the link to the full video if you are interested in the geometry part of it too.
  9. In this weeks episode (Episode 11) of The Grand Tour, a motoring show with the old presenters from Top Gear UK, there was a section in the show were physics played quite a big role in getting a shot right. In the shot they fired a car, assumed off of an air cannon, onto a boat. In order to do this somebody needed to calculate using kinematics how far the car would go given a supplied force. Taking what was shown in the show it is quite difficult to try and guess exactly how they did given there is too many unknown values. I can imagine that they also took some air resistance into the calculation as they landed the car almost directly on the boat. Lets try to find how far the boat is from where the car is launched. In the video the car seems to be launched from a fairly low angle, lets say 25°. I can also tell from the video that the time the car enters the frame to the time it comes in contact with the boat is close to 2.5 seconds, taking into account they didn't slow the footage down. With this time we can use the equation to find it's initial velocity using Vf=Voy+a(t/2). With this calculation we find that Vyo is 12.25 m/s. Using some trig we can find Vx=(12.25/tan(25)) which leaves us with a Vx of 26.27 m/s. Then using ΔX=Vot we can find that the distance the car has to travel is around 66.88m.
  10. The liquid, solid, mixture I like the most is water and dry ice in a sealed container. Very nice explosion.
  11. I remember the one lab we did were we made little speakers, it was fun yet difficult. It makes me appreciate what the engineers do to make proper speakers sound so good.
  12. I saw something like this once, completely through a browser using OpenGL. It was quite impressive.
  13. What's fun is you can enable different forms of 'colorblindness' on your phone to simulate the effect.
  14. Awhile ago in class, our table group got in quite a heated discussion on which breakfast food is the best. Now the other side, pancakes, tried their best to convince me of the qualities that make them better than waffles. They brought up point such as fluffiness, and taste, but they failed to ignore that waffles can also have both of these properties. The way to achieve these properties is the cooking time and the temperature. In order to get maximum fluffiness, cooking for a lesser amount of time does not let the batter cook quite as much. Some points that I would like to bring to the table that make waffles way better is the increase in surface area that increases the flavor. Another feature that makes waffles much better is the pockets that holds the butter and the syrup. Lastly waffles are much better because they are much faster to make as both sides get cooked at the same time.
  15. There's a YouTube channel that I watch called SmarterEveryDay, in one of his more recent videos he used a slow motion camera to see how a bullet would effect a Prince Rupert drop. Before I talk about the video I will first explain what a PR drop is. How they are made is some molten glass is dropped into some cold water, creating an incredibly strong price of glass. However everything has a weakness, in this case it is the tail of the glass piece which is incredibly fragile. The hardness of the glass comes from the rapid cooling creating a bulb that has a cold exterior that pulls inward on the hot interior which pushes out. These forces equal to something that is bullet proof. And here is another video of his showing the properties of the PR drop.