ally_vanacker

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Blog Entries posted by ally_vanacker

The highest a rabbit has ever jumped is 99.5cm in Denver on June 28th, 1997. to convert that into meters the measurement would be .995cm. from this information I gathered I also know that at the moment the bunny began to jump the initial velocity was 0m/s. also, since the bunny jumped on Earth I know its vertical acceleration had to be 9.81m/s^2 due to gravity. From all this information I can find how long the rabbit was in the air for. By using my three variables, I can use the d=vit+1/2at^2. Because initial velocity is 0 I can get rid of vit and make the equation equal to time since that it was I am solving for. My new equation to get time is t=2d/a all under a radical. Next, I substitute my three variables- initial velocity, distance, and acceleration, with the numbers a units and plug this into my calculator to get 0.45 seconds. Since the rabbit went a distance of .995cm up and had to come back down, I have to multiply the time by two. This leads my final result of the world record rabbit hop to be .9 seconds in the air!
While looking back on last week, our catapult taught me a lot about physics and also allowed me to use my problem solving skills. The catapult taught me about what angle to have the ball launched at, how adding more force to the catapult would make it go further, and also how height and speed affects the outcome of the catapult's results. But getting to the end result on Thursday was a result of loads of frustration and struggle. For example, Kylee, Grace and I had many trials and errors throughout our time together. At one point we spent an hour after creating it just trying to figure out how it would possibly ever catapult a softball. We had to be creative and make many different structures to get the ball to go forward. Also, we had to get creative in keeping two boxes of salt connected to the catapult without them falling off. After many slivers and moments of frustration and torture I am proud to say our catapult was as success.
Typical Kylee and Mandy are always going back and forth and one day decided to fight and pulled the net when they should have been setting it up, with good old Quinn trying to get them to stop. This created two tensions pulling on the net- Kylee and Mandy- and Quinn in the center being "the dot" motionless in the center. Kylee, being taller and weaker, pulled the net at a 30 degree angle above Quinn with a force of 30N. While Mandy, being shorter and stronger, pulled the net at an angle of 20 degrees with a force of 32N. I drew this diagram and then wasn't too happy with how the angles looked and broke it up into happy components to create a new diagram. To find the components I used the equation Tcos(x) and Tsin(x). On my x axis I used the equation to find that Mandy had a force of 13N in the x direction and Kylee only had 5N in the x direction. Next, I can use Newton's 2nd Law Fnet=ma and solve for the x axis by plugging in 13N-5N=ma. I then realized that acceleration in the x direction is 0, so ma equals 0. From there I solved for the x axis and got a force of 8N that Quinn had to battle against!
Throughout the day I have started to realize that physics is part of everything I do. When I wake up in the morning and my alarm goes off I usually follow Newton's first law and stay at rest for a little while. Once I finally get out of bed I use heat to cook food so I can have a good breakfast before school which is using thermodynamics. Next, I get ready and drive to school. While driving I realize that gravity is keeping my car on the road and the normal force of the road is pushing back on my new Volkswagen Beetle as a drive. There is also friction on the road and my velocity and acceleration increase and decrease as I come to red lights and stop signs. Also friction with my brakes helps me slow down and come to a stop. Once I safely get to class, I sit in my seat all day and gravity keeps me and the chair on the ground and the normal force of the chair pushes back. After school I go to volleyball practice which includes a lot of physics. For example, when throwing and serving a ball, different trajectory allows the ball to go further or shorter distances. Also, when the ball is in the air, there is some air resistance and gravity also does its part as the ball bounces back on the gym floor. Another example would be spiking the ball and the velocity of the hit. At many times in high school I can recall people complaining that what they learn in school will never relate to real life but physics has been able to prove that something in school actually does!
Physics can be seen in every sport. To start off, physics can be seen in the first second of a volleyball game when the ball first rebounds off the hands of a player during the first serve of the game. Factors such as, how good a server is, where the ball is being served to, and how high the serve goes was taken into account as I did my testing of how long it took the average volleyball player to serve a ball to the center of the court. By using a stopwatch and various trials I found the average time the ball took to be 1.11 seconds from the contact of the players hand to the ground on the opposite side of the court. I also know that a volleyball court from the serving line is 30 feet on both sides so serving the ball from one side to the center of the court on the other side is roughly 45 feet from the end line. To make all my units equal I converted feet to meters and got 13.7 meters. After gathering all this info I am able to find the velocity of the ball by using the equation d=vit+1/2at^2. Since the ball is traveling horizontally I know the acceleration is zero. Because of this I can get rid of the 1/2at^2 and use the equation vi=dt to solve for velocity. Next, I add numbers and units to get (1.11s)(13.7m)= 15.2m/sec. From this I can conclude that the average speed at which a girlsâ€™ volleyball player can serve the ball is 15.2m/sec.
I recently passed my road tests and have had many experiences while driving with the physics we have talked about in class. For example, when I took my test it was snowing and the roads were very icy. This made it harder to drive because the conditions of the road created less friction on the tires making it harder to stop. Another thing that has proven to be true while driving is Newton's third law which is that every action has an equal and opposite reaction. I'm nothing close to being a good driver and many people have asked me how I even passed my road test due to the fact that my moms mini van has been subject to Newton's third law. I've hit many curbs and piles of snow but they also hit me back and have left a few new dents in the car!
One day I took my little cousin to the zoo and while we were in the monkey house getting out of the snow he saw the big yellow circle and wanted to throw a coin in it to see what it did. While it spun around all I could think about was physics class and how we learned about centripetal acceleration. When we first dropped the coin it went slowly around in a circle and then it kept speeding up as the radius got smaller. This proves the equation of v^2/r to be very accurate because by the time the coin was about to fall in to the dark center it was moving so fast you couldn't even tell what shape it was. From this experience the idea of centripetal acceleration was put into real life for me.
This quarter I put in place the not strategy of drawing pictures and being more creative while note taking rather than just getting through it and not getting much out of it. I enjoy drawing and making little doodles so this seemed like a fun idea when it was introduced to me in class. The best part about it was it honestly did help. I had fun making it look good which made me spend more time focusing on physics and watching the video in greater detail. Before I did this it was easy to just skim through the video and jot down what was written on the screen but taking notes with pictures forced me to think harder about the concept.
I recently found out that it's proven that you can't throw your phone in the air without it flipping the short way at some point because of physics. I've never learned about this concept before but I did some research on the always trustworthy google and got an answer on why this is. The axis theorems in physics force this to happen because of the difference in inertia from when the phone is the long compared to the short. Because you are not flipping the phone perfectly along the axis it deviates and will go to the other axis. This is also true with other objects like books. I looked up the math and equations to figure all this out and it seems like a very complex topic but also makes a lot of sense with the different axis of an object and the way the inertia will cause it to respond.
Everyone loves candy and physics can make the candy eating experience longer! Physicists did a study with hard candy and found that the candy dissolves linearly. This means that the rate in which it dissolves stays constant instead of accelerating at any point. Therefore, if you keep each candy in your mouth without biting on it, each piece should last about twenty five minutes. This shocked me cause one tiny skittle doesn't feel right to take almost 30 minutes to eat. From this experiment, I think physics can answer many real life questions but I doubt I'll take that long to eat candy at any time in my life!
Sound waves can help whales hear each other and communicate under water. Since the medium of these waves is water, the sound waves can travel much faster than humans talking on land. Medium is the main thing that can affect wave speed so whales are able to communicate quickly and other animals underwater also can too. Also, as the depth of the ocean increases as the whale goes further down the water gets colder which causes the speed to decrease. Temperature and pressure changing throughout the ocean can impact the sound waves of whales. A special case for these sound waves is the sound channel. the waves are able to travel thousands of miles and people have used technology to detect that they can hear sounds of whales many kilometers away in the ocean. Animals underwater must have a lot more fun communicating because the medium they are in!
While researching and learning about the Doppler effect I came across the idea some people have that there is an inverse Doppler effect. Researchers from Britain did an experiment in the early 2000's trying to prove that the Doppler effect could be reversed. They did this by creating a pulse that acted like a siren and then using radio frequency to see the waves. This was done on structure called a nonlinear transmission line that used magnetics and created a new type of wave. They observed that instead of the waves getting looser like the Doppler effect shows, the waves actually got tighter and frequency increased. They claimed this proved that there may be an inverse Doppler effect. I don't believe that in real life the inverse Doppler effect can really be shown but the Doppler effect is seen everyday.
While driving on the expressway I have passed by many police officers and like everyone around me, slowed down the second I realized it. The radar guns police use, use physics to help find out if the driver is going too fast. As the police officer aims the radar gun at cars passing by, the gun sends out radio waves toward the car. Then, the radio waves hit the car and bounce back toward the gun. The gun then measures the frequency of the returning waves, so the faster you are going toward the police radar gun, the higher frequency the waves will be. This concept uses a lot of physics including radio waves, frequency and also the Doppler effect. Since the car is moving toward the gun, the frequency of the returning radio waves will be much higher.