prettybird

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About prettybird

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  1. Last night, I went out and saw the movie Split. I was slightly intrigued by the reviews, and it was said to have a really surprising ending, so I put aside some of my personal opinions on the topic of choice and watched it. It was a very interesting movie to say the least, and if you're planning on watching the movie, I would stop reading here, because in order to get into some physics I have to spoil the ending, which is entirely the best part. Okay, now that you're sure you want to continue, the movie is about a man with 23 distinct personalities inside him, which all take control at different times. While one, Barry, is in control, he kidnaps three girls. Three of the personalities (Barry, Ms. Patricia, Hedwig) believe in a figure called the Beast. The spectators find out that the Beast is not a figment of their imaginations, but actually a 24th personality that has super powers. Just by switching to this personality, the man's body becomes impenetrable and extremely strong. The only surviving girl, Casey, tries to shoot him with a shotgun and the bullet essentially bounces right off. That's where the physics comes in. How much force would a regular shotgun shell impart, and how strong would this man's skin have to be? A 1 oz. shotgun slug leaves the shotgun at 1800 fps, or about 550 m/s. This slug would weigh about .03 kg, giving it a momentum of 16.5 kg m/s. Assuming that the bullet was only in contact with his skin for .001 seconds, and it was a perfectly elastic collision, the force imparted onto his skin would be 16500 N. The only metal I could find info on was steel, and it can withstand 40 kN, meaning that his skin could withstand atleast half the force steel can.
  2. Personally, I don't like fishing and I believe that if you aren't going to eat the fish it's cruel, but I was playing Stardew Valley and I had been doing a lot of fishing when I started thinking about the physics of fishing. If a fish is on the hook, you start to reel in the line. As you do this, you created tension in the line. If the fish is able to produce a larger force in the opposite direction of this tension, the line will unroll a bit more. However, if the tension in the line is creating a bigger force than the fish can exert in the opposite direction, you will be able to reel in the line more and the fish will accelerate forward. While doing this, you are also working against the force of friction from the fish and water, so you have to be careful not to snap the line by creating too much tension.
  3. Hanging a picture can actually show a lot of physics dealing with force and friction. First, you have to hit the nail with a hammer into the wall. Each time you hit the nail, you have to overcome the force of friction between the wall and the nail to get it to go in further. The hammer rebounds back after hitting the nail and you feel the force in your hand. Then, depending on how heavy the picture you hang is, the wall has to exert a force equal to m*g on the nail to overcome the combined weight of the picture and the nail. If it exerted a force less than mg, the nail and picture would slide down the wall, leaving you with a large crack. Any larger than mg and it would accelerate upwards. If you have two nails, the picture can be better supported because the wall can split the same force between two, so for a heavier picture use more nails.
  4. One equation in physics is torque, which is the Force applied to object to rotate it about an axis times the radius the force is applied at. Torque only takes into account the force perpendicular to a surface, because any other direction will not cause it to spin. When you open up a laptop, either with a force at some angle or directly perpendicular, the force acting perpendicular causes a net torque and spins it about the axis. The same can be seen on doors, and even books. Also, some caps that come on hinges, like a lotion bottle, can be described in this way. As long as some of the force is directly perpendicular, the surface will move in the way it is being pushed or pulled.
  5. I had an incredibly weird dream the other night. I was driving with my mother and in front of us was a man on roller blades using two machine guns taped to his arms to propel himself forwards. I was about to forget my dream all together until I started thinking if physics would allow such a thing to happen. Similar to the way a rifle would recoil when a bullet is shot, the machine guns would recoil when the bullets are shot out of them. Normally, they are anchored to something so the recoil is hard to notice. However, the force exerted on the machine gun would then be exerted on the man, whose body would normally compensate and return the machine gun to its original position eventually. Since he is on rollerblades with little or no friction (it's my dream, I'm neglecting friction), the force would propel him forwards. And since he was firing them at a rapid rate, this would in turn propel him forwards at a decent speed. So, while this is an entirely reckless, irresponsible and dangerous idea, it is physically possible to achieve.
  6. I used to wonder why the pendulum in a grandfather clock was there, and I originally thought it was for purely visual interest. Now, I realize that the pendulum acts as a pendulum to keep the clock working at exactly the right time. The pendulum has a period of 1 second and each time it swings left or right, it moves the clock through one second. But what length should the pendulum be in order to keep time at 1 second? The equation for the period of a pendulum is T = (2* pi) (L/g)^(1/2) and when plugging in the value of 1 s for T and 9.81 m/s for g, you get that the length of a pendulum to keep time correctly is about .25 meters.
  7. One of my more recent favorite games has been Stardew Valley. It is essentially an updated version of the game Harvest Moon, which originally came out in 1997 on the Gameboy, which is what I originally played it on. It is a game where you inherit a farm from a dying relative, and you come to find it overrun with weeds, trees and rocks. You slowly clear it out, plant crops and adopt animals. You can also mine and fish, and you slowly build relationships with the people in the town by joining them at festivals or bringing them gifts. You also have the opportunity to start a family. For the most part, the game seems fairly realistic. You have to bait your fishing rod, it takes alot of hits to chop down a tree and you lose energy the more you preform a task. However, the mine introduces something that really breaks physics in this game. The first mine you journey into have 120 floors, and when you reach the bottom you receive a skeleton key. Once you unlock the desert, you have the chance to open another endless mine Two things here are the problem. One, this mine is truly endless, and at some point you would not be able to go any farther because you would hit the center of the earth and just burn up. Also, you can find holes which allow you to drop down levels. Not a ladder, like how you progress most of the game. It is a literal hole you must jump down. I have seen someone jump down 11 floors at one time. Now, it does take away some health, but assuming that each floor in the mine is around 6 meters minimum, you would fall 66 m, meaning you would be falling at around 36 m/s by the end of your fall. This would surely cause a bone to break, but you come away unscathed.
  8. One comment I received on a previous blog about backpacks was about a backpack literally breaking your back. I decided to do some research on the topic. It appears that a vertebrae in your spine can withstand about 500 lbs of force, which is about 2225 N of force. In order to do some damage to your spine, you would need to have a backpack weigh this much in newtons. This means that your backpack would have to have a mass of 227 kg, or almost 500 lbs to do real damage to your back. To put this in perspective, I estimated that a relatively full 2 inch binder is about 5 pounds on average. This would mean the backpack would have to hold about 100 binders to do damage. No only is it near impossible to fit that many binders in a backpack, and so you would have to have one specially made, but you would also have to have a group of people or even a small machine help you lift it onto your back in order to actually do the damage. Long story short, I don't think a backpack will be breaking your back any time soon.
  9. I've heard the same principle (sort of) applies to those who lay down a bed of nails. Their weight is spread over so many nails that there is very little force on each nail.
  10. Pancakes are way better, the softer surface is more porous, allowing syrup and butter to soak into it and fill it with flavor.
  11. That must have taken a lot of work, I'm glad they were more precise than we were in the lab we failed at in class last quarter.
  12. A real Death Star would probably also affect our moon's orbit, which would then affect the tides and water levels on Earth.
  13. How much force do you think it would actually take to move the ground the way some of the "ground pounds" are displayed in some video games?
  14. Do you think it would ever be possible to have a small weapon harnessing sound in real life? That would be a cool weapon to see in action.
  15. In the winter time it seems that everyone is shocking each other. I shock myself on every chair at school, I swear. The worst feeling however, is when I shock my cat. Most of the time it happens when I'm petting her. The reason why is that when I pet her, I am picking up electrons from her. This gives her a net positive charge and myself a net negative charge. I don't know the magnitude of the charges but we would have equal and opposite charges, assuming I am not grounded and my body contains the electrons, the same with her. When I go to pet her again, our net charges come into contact, and the shock comes from the electrons "jumping" back to her fur and leaving my body. The same sort of thing can happen when you are wearing fuzzy socks or slippers. When you walk, you scrape electrons off of the fabric, and when you go to touch someone, the excess electrons jump onto them in the form of the shock. Likely, part of the reason why you seem to shock more people during the winter is that you wear warmer shoes or socks during the winter, and these items act as better insulators, preventing the net charge on your body from leaving to the Earth.