Blog 6: Water Slide Fun

This past weekend, I was going through some old photos because I was helping my mom transfer all our files from our old computer to our new one. I came across this picture of me on this waterslide at the old Hawaiian Waters Adventure Park. I realized all the physics going on in this picture. My weight is pulling me down to the slide and there is a normal force from the slide is pushing back on me, but the two forces aren't equal because I am a slide, so the forces affect me at an angle. Also I am doing work and there is change in energy.

At the very top of the slide, when I was waiting for the lifeguard to say that we could slide down, I only had potential energy. I could've calculated my potential energy by multiplying my mass by gravity and the height of the slide. At the base of the slide my energy was entirely kinetic and it was equal to my potential energy at the top of the slide. Also even though I was on a mat and there was water flowing down, there was still some friction that helps determine how much work I was doing. Or I could have calculated my change of potential energy or kinetic energy to find my work.

Blog 5: Momentum in Volleyball

This past week when I was at my club volleyball practice I was thinking of all the momentum involved in the game. If the hitters get a good set, they try to hit the ball with the most momentum they can while still being accurate. The passers in the back row, tries to control the momentum of the hitter's hit by digging the ball. Sometimes if there is too much momentum on the ball, the passer can't control the momentum and guide the ball to the setter, this results in a shank. Also the blockers try to totally stop the momentum of the ball so it goes back to the opponent's side of the net. Or they slow down the momentum of the hit by touching the block, which makes it easier to pass the ball. Every time the ball is contacted a collision occurs.

As a libero, or a defensive specialist, I constantly have to dig the hitter's hit. If the ball is coming at a fast pace I strive for the collision of the ball and my arms to be inelastic, so the momentum would be conserved, but the kinetic energy wouldn't be conserved. If the kinetic energy isn't conserved, with my dig, I would be able to slow down the ball and guide it to the setter.

Blog 4: Roller Coasters

I was looking through my old volleyball trip pictures again and found more pictures that related to physics. These pictures were from the same trip as my other blog. On our way home from the volleyball tournament we stopped over in Vallejo, California and went to Six Flags. I realized that all the roller coasters we went one had potential and kinetic energy.

The roller coaster in the picture pulled us up the slant backwards and then it shot us forward at a great speed. As the roller coaster was pulling us up the slant, we were gaining potential energy because our height was increasing. When we reached the top of the slant, we reached the maximum potential energy of the ride. Also when we arrived at the top of the slant, the roller coaster stopped to keep us in suspense and we had zero kinetic energy. As we came down the slant we were gaining kinetic energy because we were accelerating and we were decreasing in potential energy because our height was decreasing. The factor that affected our potential energy was the height of the roller coaster and our speed affected our kinetic energy. Since our mass stayed constant, it was irrelevant to our potential and kinetic energy.

Blog 3: Going With the Flow

This past weekend, I was looking at some old photos from my previous volleyball trips. I came across this picture of my friend and I swimming in a river in Reno. As you can see the current was very strong and there was hardly any friction except a few occasional rocks. We would have traveled at a constant speed all the way down the river because our net force would be zero, so we would have no acceleration. To prevent ourselves from floating all the way down the river, we started to swim against the current to create friction and a net force. We would still have a positive acceleration until the friction caused by our swimming was greater than the force of the current. If we were stopped by a rock on the way down the river, our net force and acceleration would also be zero because friction would equal the force of the current. I realized that this is a great example of Newton's 2nd law.

Blog 2: Projectile Motion

This past weekend, my cousin and I were playing in my grandma's back yard waiting for the UH football game to start. We accidentally hit the ball over the roof and to go to the front of the house to retrieve the ball. Instead of just getting the ball and walking it back to the backyard, my cousin said he could throw the ball over the whole house. I instantly thought of projectile motion and went inside to get my camera to record the motion of the ball. Using kinematic equations, I could have figured out the approximate vertical velocity he had to throw the ball with in order for the ball to get over the roof and land in the backyard. I would've had to known the exact height of the house, how far the ball traveled in the x-direction, and the final velocities of the ball. The roof is gabled so the ball would have to be at it's peak at the highest point of the roof, but my grandma's roof has a metal roof attachment, so the peak of the ball doesn't match the peak of the roof. The first picture is of my cousin throwing the ball from the ball from the front of the house, the second is of the ball approximately at it's peak, and the third is of the ball almost landing in the backyard.

Passing Physics

This weekend as my team and I were warming up for our game, I realized that volleyball has a lot to do with acceleration, velocity, and displacement. The ball always travels at many different speeds and varies in acceleration depending on how hard it is contacted. Also vertically speaking, the displacement of the ball will always be positive if the ground is considered the origin.

Since volleyball is influenced by acceleration, velocity, and displacement, kinematic equations can often be used to determine the speed of the ball and how far it will travel. As a libero, I have to pass a lot of serves and hits. If I can measure how fast the ball is traveling when I pass it, the acceleration of the ball, and how long it takes for the ball to reach its peak, then I can use the kinematic equations to determine the height of the peak of my pass. With these calculations I can see if I need to add more acceleration to get a higher pass or slow the ball down to lower the height of the pass. I can also calculate what speed and acceleration the ball must be moving to pass the ball a certain distance. As I begin to understand physics more and unravel all its concepts, I think I will be able to find more relations to volleyball.