Ball It Up-Flash Back

I was going through some old video footage of my basketball days back in the days (junior year). I found a clip of me making a basket and realized the ball was a projectile. Now you may be saying, "I know what a projectile is." Well you may know the general idea of a projectile, but the more conceptual physics way of describing it is: Any object in the air having a set path with gravity as the only force that is influencing it. Oh you already knew that? Well did you know that in the case of my shot of the basketball into the basket, the ball has a vertical and horizontal plane it is travelling in. With these two components together my ball moves in a diagonal pattern. Since gravity is acting on the ball, the ball will follow a parabolic type path as the ball goes up reaches it peak (where its vertical velocity is zero, horizontal velocity remains constant) then comes back down. With the correct trajectory the ball goes into the basket. Oh you knew all that too? Oh well I thought it was cool.

The Physics in Science Fiction

The topic of outter space has been coming up recently in physics class. It has reminded me about movies and books like 2001: A Space Odyssey, A Hitchhiker's Guide to the Galaxy, and even Star Wars. There are a lot things that defy physics in these books and movies which is cool but there are a lot of things that correspond to real physics which is even cooler. One thing that corresponds to what we are learning recently is space stations. In order for humans that live on space stations to feel the same gravitational force they would on earth the space station would have to some how create 1 g of force on the station. This can be done by manipulating the radial distance and the rotational speed. A space stations radial distance would have to be large enough to make the effects of different g's on your body go away. The larger the radial distance or the faster the speed the more centripetal and centrifugal force there would be. Centripetal force are the forces that keep an object in a circular motion and centrifugal force is a sensation or feeling of an outward force because of the inertia or natural tendencies of your bodies motion. It's pretty cool that artificial gravity could be created in outter space and the method is something that I actually understand. Science fiction is pretty cool.

Inaccurate Lyrics

The other day I was listening to the radio and I heard some lyrics that were inaccurate, physically speaking. The words were "the work I've done trying to move this immovable wall..."

These words are incorrect according to equation work=force x distance. No work is being done on the wall if it does not move any amount of distance. While work may be done with the person's muscles, no work is being done to the wall if the wall does not move even if he is pushing with all the force in the world. It is pretty amazing that I am hearing physics in music I listen to. I never thought I would think about school things when listening to music. That shows you anything is possible. I think I will try not to write anything physically inaccurate in my songs unless it gives another dimension to my music and I recognize it.

Ball Bounced Off His Face!

Well it's volleyball season now. It is quite different from basketball but at least I get to pound volleyballs into opponents faces. That is always fun. Actually that's what I want to talk about. The force at which a ball bounces off a person's face is greater than if a ball just hit someone's face and fell to the ground. If I were to bounce a ball off a person's face the mass of the ball times the speed of the ball hit plus the speed of the ball after it bounces is the momentum. A ball that just stops would only be the speed the ball was hit plus zero because the ball came to a stop. The ball that bounces has a greater change in momentum which also equates to a larger impulse. So if you see a ball bounce off someone's face you know that hurt way more than if a guy stopped a ball with his face.

Hmm Momentum...

So this has been a tough weekend/week for me. I was starting to get sick before the Basketball State Tournament but it has gotten worse since then. I may have also cracked a bone in my right foot and oh we lost to Kahuku in the semi-finals of the State Tournament. Now I want to talk a little about momentum because momentum was a key factor in our loss to Kahuku. The equation m1v1+m2v2=m1v1f+m2v2f is the equation that will explain the charging call I got against me as I went up for the shot that would tie the game. No momentum is lost in a system because what one object gains the other objects loses. So basically the overall change in momentum in a system should be zero. Now the system in our basketball game was me and the opponent. As I was driving into the basket I saw my opponent come over to take a charge against me so I came to a jump stop. His mass being more than mine as well as my decreaing speed was not enough to knock him over in my opinion. His advantage in weight and speed should have resulted in my movement going backwards instead of his. So what is the explaination to his falling down backwards. I might have to say he "flopped." I'm sure if I had the exact mathematics I could prove that I did not hit him with enough force to knock him backwards like the way he fell. If only the referee knew physics he might not have costed us the game.

The Ball Pushes Me Back?

Ok well I have been playing basketball for quite some time now and not once have I ever thought the ball was pushing me back with the same force that I was pushing it at. Seriously, this concept is super strange. Newton's Third Law of Motion states that when one objects applies a force on a second object, the second object applies an equal and opposite force on the first object. Well I can see how this law works with guns with its recoil but a basketball pushing me back is kind of far-fetched. My skeptisism is easily answered with the concept of action and reaction forces relative to mass. Since the mass of the ball compared to my body mass is so small my body will not accelerate backwards as fast as the ball will accelerate foward. So basically even though the ball is pushing back at me with the same force that I pushed it at, my mass being much greater, my acceleration goes unnoticed, while the acceleration of the ball is noticable as it cleanly swishes through the basket for the game winning shot.

Bartenders, Drinks, and Inertia

Ah back to writing journals again. A new semester, a new journey to embark on and learn how this world really works. It's like a new season of your favorite show. Now down to business.
The other night I was performing music at a restaurant/bar. You know the music was awesome with me singing and playing some crazy guitar licks and the drummer laying down some sick hip-hop and rock beats. During one of the breaks we were thirsty, so we go over to the bar to get some drinks. We are underage so we order water and orange juice, of course. The bartender sends my orange juice flying at me across the bar and I stop it with my hand. At this point in the year my brain is set to notice anything physics the instant it happens. This hurts my brain sometimes because everything that is going on is always physics. But anyway...my brain tuned into the property of inertia and the forces that act upon objects to keep them in or out of equilibrium. First off the pitcher of orange juice that was flying at me needed a force to act upon it in order to move from its state of rest. The bartenders thrust took care of that. When the pitcher was moving, according to the property of inertia, it would keep going until a forced acted upon it to stop it. In this case it was mostly my hand and some friction that stopped the pitcher. There were also other forces like gravity and the support force of the counter. When I stopped the pitcher with my hand, the orange kept moving in the direction the pitcher was thrown because my hand stopped the pitcher not the orange juice. This shows the property of inertia in action. If there were no forces to act upon the pitcher and the juice it could have gone on forever like it would in a vacuum. I did not have a camera handy when the bartender slide my O.J. toward me so I had to recreate at home but the picture shows the concepts talked about in this blog.