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Everything posted by Celeena

  1. Celeena

    Horse Jumping

    Most horses have four gaits that they commonly use. The first, the walk, is a slow, tame, four beat gait. The trot, slightly faster, is a two beat gait. The canter, a three beat gait, has a rocking feel to it. Last but not least is the gallop, which is a fast four beat gait, averaging about 25 mph. The most comfortable gait for a horse to jump from is the canter. This is a consistent gait that allows the horse enough momentum as well as an even pacing so that an adequate amount of force can be used during the takeoff. My trainer has told me that there are five components to a jump, all important in making sure that you complete it safely and well, gracefully. The first is the approach. Approaching the jump means that you must prepare at the correct angle, make sure you have enough room to count out the proper stride length, and give yourself time to think about whether you need the horse to go a little faster (a small nudge with your calves), or slower (a half-halt, pulling slightly with both reins and then releasing), in order to glide into phase two safely. Phase two is the actual jump itself. When jumping, the horse exerts a force on the ground in order to push itself upwards. This can be represented by Newton's second law or F=ma. Horses can carry up to 30% of their body weight. While this is impressive, it is also a limit. When the horse exerts all of that force on the ground, the ground exerts the same force back. This can seriously damage their back legs if the rider is not careful. Phase three of the jump is the air time. While the horse is in the air, it is the rider's job to not only sit up, releasing the pressure on their back, but make sure that their landing will be comfortable and set them up correctly to continue the course. During their time in the air, the horse has only potential energy, compared to it's kinetic energy during the approach. At the horse's maximum height, the velocity is zero, meaning the only force acting upon horse and rider is gravity: 9.81 m/s^2. Phase four is probably the most dangerous phase of the jump, not only because there is a large force between the horse's front legs and the ground, but also due to the fact that all of the rider's weight is put onto the horse's front legs as well, causing a large strain. Again, if the rider does not properly care for the horse, all of this weight and force could potentially damage it's legs. Phase five, or finale, is after the jump is completed. The velocity of the horse should return to that of the velocity during the approach, meaning the sum of the forces during the entire jump should be equal to zero. The rider should check to make sure the horse is on the correct lead, and proceed to evaluate their next jump, repeating step 1.
  2. As someone who is interested in sports, it is always fun to see physics in each individual sport that I participate in. Bowling requires an interesting amount of physics, not only in the way the ball is thrown (or rolled), but also in the way that the ball is made. My bowling ball, is made with a weight block in the middle of the ball and a hard outer shell. Any time you purchase a bowling ball this is the case, unless it is a spare ball which is entire plastic and does not spin at all. The weight block comes in different shapes and sizes and is why bowling balls vary in style and price. The location, size of the weight block as well as the location of the finger holes all factor into how much and how well the ball is going to spin. The more rotations, the better the impact on the pins. To throw a proper "strike" you want the ball to hit between the head pin and the pin to the right, or the three pin (for right handed bowlers). Understanding the physics in the sport can help because the degree to which the ball strikes the pins has a very large effect on the reaction of the pins. Controlling the degree to which the ball strikes (haha, strikes... bowling pun) the pins is essential in getting good marks. Obviously there are other factors such as the velocity of the ball and the oil pattern on the lane, but those will be adjusted with time. In order to improve your bowling skills and rack up the strikes, you must first understand that angles are everything, and reactions only occur when the angles are at the right degree.
  3. Celeena


    Did you know that in many ways, the planet Mars is much like the planet Earth? The small "red" planet has seen volcanic eruptions, meteor showers, shifting tectonic plates and even dust storms. The planet even has growing and receding polar ice caps, that show changes in seasonal temperature. Mars is a terrestrial planet, along with Earth, Venus and Mercury. Mars is too cold and has too thin an atmosphere to allow liquid water to exist at the surface, but evidence clearly shows that about 3.5 billion years ago, Mars was thought to bear a lot of water, even existing in small streams and lakes. This planet is one of the planets closest related to earth, in terms of sustaining human life. The force of gravity on this planet is 62% less than that of Earth, however, therefore if you weighed 100 kilograms on earth, you would weigh 38 on Mars. I find our solar system to be a very complex and interesting group of planets. There are 8 planets in our own solar system, but that does not mean there are only 8 out there. There are hundreds of billions of galaxies out there, consisting of their own planets that could potentially sustain human life as well. Think of all the possibilities out there!
  4. As someone who has spent the better half of her life on top of a 1000 pound animal that could kill me at any second, people who tell me "horseback riding is not a sport" just might receive a punch in the face from me. First, let me tell you that I could probably beat you at arm wrestling among other strength tests simply because I have to carry large bucket of water around the barn, lift hay bales, and 50 pound feed bags. All of the work in the barn makes me sore and at that point, I haven't even gotten on my horse yet. Those who play football and soccer may get beat up a bit, but when they fall, it's over their feet. I fall over 5 feet and it's on either the gravel or a hard dirt arena. Last time I checked, a soccer ball doesn't have a mind of it's own, and a football isn't going to kick you in the face if you accidently walk behind it without warning. There are multiple reasons why horseback riding is a sport and I'll most likely get into more detail later. Before you go up to an equestrian and tell them that horseback riding isn't a sport, just think for a second about what you're saying. Go jump on a football player, kick them in the ribs and tell them where to go. Now go do that on something ten times bigger and don't forget that horses don't speak English! Nonverbal cues only, and do it flawlessly.
  5. Celeena

    Elephant Pee?

    I recently read an interesting article that explored the question "How fast does an elephant pee?" David Hu has a so called "Law of Urination" that says all mammals relieve themselves in the same amount of time. An elephant has a bladder that is almost two feet tall and holds a lot of urine. The amazing part of his experiment isn't in the fact that an elephant can hold approximately 42.3 gallons of urine, but in the idea that the elephant can empty his bladder in teh same amount of time as a 20 pound dog. As a physics student, I realized that it would make sense in the idea of the urine accelerating toward the earth at 9.81 m/s^2, but does the force at which said animal projects it's urine matter? The answer: No. Just like many of the questions we have already answered, if we dropped two balls from the Eiffel tower, one with a weight of 30 grams and one with a weight of 140 grams, they would both reach the ground at the same time regardless of the initial downward force. I swear that I was not trying to gross everyone out... I just found this to be very interesting. For more information visit: http://www.popsci.com/article/science/how-fast-does-elephant-pee
  6. The first month of physics has gone by extremely fast. I have learned that physics is essentially everything around you, most people just don't know that! Kinematics has been exciting for me, because I like math. I like the idea that there is a definite answer for everything, and when looking for an asnwer (i.e. acceleration, initial velocity, distance, etc.) there are multiple ways to solve it. I also like the fact that there are many different equations that you can use, and when one doesn't fit with the information you have, you can just move onto another one! I would like to understand more about how gravity and air resistance effects objects in motion. I love connecting phyiscs to horseback riding, and I would like to understand more of how it connects to jumping horses.
  7. I totally want to travel too! We definitely need decent jobs if we're going to go to different countries!
  8. I had no idea you were a captain on the swim team! That's amazing!
  9. Celeena

    About Me

    Hi! My name is Celeena, and I'm a huge fan of anything baseball or hockey related. I'm in 3 different bowling leagues, I've been playing violin for 9 years, and I love a good game of ultimate frisbee. I am also a competitive horseback rider and own a horse named Indie. My plans for after high school are to attend college and become a dental hygienist. I chose to take Physics this year for a couple different reasons. #1 Because I already took Biology and AP Biology as well as Chemistry, and I thought that Physics would show that I am a well rounded science student. And #2 because I enjoy science classes and learning about what they have to offer. Sometimes theories exhaust and frustrate me, because I like a lot of factual evidence, but I hope to gain a better understanding of energy and motion and what else goes on in the universe.
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