Blog 6: A Simple Compromise

My dad got particularly excited about this blog as I finally asked him for an idea.  He quickly thought of ideas that were, although easy to do, way too complicated for me to comprehend.  That still did not stop him from shooting down my more simple and "fun" idea.  My idea was to grab the small step ladder we have in the kitchen, put a stuffed animal or something on one of the blades, and steadily increase the speed of the fan.  But, with more concern for the ceiling fan than the entertainment factor of doing a physics blog, my dad came up with a satisfiable compromise.  In this set up, my dad screwed a paper plate on to one of his power drills.  I placed a nickle on the platem started the drill slowly then started to turn up the speed.  Soon after increasing the speed, the nickle flew off the plate.  I now know that because the nickel's centripetal force, in this case it's friction, was not strong enough to keep it in it's circular path, it flew away from the center of the rotation on a tangent.

Angled Ramp (turn before tunnel on Likelike Hwy)





Blog 5: "Put your momentum behind it!"

When learning how to kick a ball properly, my coach always told me, "Put your weight behind the ball."  What my coach meant was to not just swing at the ball from your knee while standing still, but to run at the ball to run through the ball and kick from your hips.  But what my coach meant was "put your MOMENTUM behind the ball."  Momentum, p, is equal to mass X velocity.  Weight, mass X gravity, is different.  In other words, it is easier to kick a ball harder if you have a starting velocity added to your mass.  In the picture, my sister has a slight forward motion (every little bit counts) before she passes the ball around the defender.  The greater your velocity, the greater your momentum, and since momentum is conserved, the ball you kick will also have the same momentum.  So, I guess that's why theres so much running in soccer...

Blog 4: Work

Kayaking was one of the funnest, althought tiring, things I've ever tried.  I've gone kayaking in the ocean in my dad's fat, plastic kayak before, but ninth grade was the first time I ever sat in a racing kayak (well actually more like fell off since first sitting in those "tippy" things isn't as easy as people make it look).  Anyway once I finally got the hang of just sitting in the kayak, I could actually start trying to paddle...my arms never burned more in my life.  Even though I could see the end of the Ala Wai canal, it seemed like with every stroke I wasn't moving at all.  The work required was too much for my weak arms.  The force I applied, even though it was over the same amount of distance as everyone else, was a lot smaller than theirs, which unfortunately made my work a lot smaller too.  But even though it was a tough sport, kayaking is definitely one of my favorites.

Blog 3

Today was the second team bonding with my soccer team.  This time we went out to a beach house in the North Shore!! So taking a break from the game, I watched as my teammates kicked the ball around our small field.  I realized that the ball was a perfect example of inertia.  The ball travels in motion travels in the same motion unless it is acted upon by an outside net force.  For example, in the beginning one of my teammates cuts the ball back and forth changing the direction of the motion by kicking it in the opposite direction.  Another example of inertia is near the middle of the video when the ball hits the tree and bounces off of it.  So even though I ended up rolling my ankle after joining the game again, its cool to know that I learned something in the process of my misfortune.

Blog 2

Cleaning out my house I normally find something I haven't seen in forever.  Normally, I find something small like a stuffed animal, or a book, but today, I unearthed our long lost Nerf Dart Tag set.  I thought for sure my mom would have gotten rid of this crazy contraption by now, finding it hidden away in a shelf, although a little dusty, was a pleasant surprise.  I realized that the small, foam darts were perfect examples of projectile motion.  The dart started off initially with only horizontal velocity and no verticle velocity, but once it was shot out of the gun, gravity began to act upon the little orange dart.  The horizontal velocity stayed constant while the vertocal velocity decreased due to gravity acting upon the object in free fall.  I never realized all the physics that went on behind the shooting of the Nerf gun, but I am glad its there to make it work or else shooting my brother wouldn't be as fun :)

Rules of the Game

I'm sitting on the the bleachers in the Moanalua gym with my friend, waiting for her little brother's basketball game to begin.  Both teams, Bulls in red, and Thunder in maroon, are on opposite sides of the court practicing their shots from different distances and angles.  As I watched the boys practice their shots, I noticed that, whether the shot when in the basket or not, the ball hang in the air for a split second before falling back down back to the court or through the net.

This made me think of the falling ball and hang time labs we did in class.  The faster the velocity of the ball, the longer it will hang in the air, so in reverse, if the velocity at which the ball is shot is slower, then the ball will spend less time in the air.
Also, the reason the ball hangs in the air is because of gravity constantly acting upon the ball once it leaves the player's hand.  Gravity's negative acceleration causes the ball's initital velocity to decrease and eventually become negative as the ball reverses directions and falls back towards the ground.

Although I never really understood the rules of basketball very well, understanding the rules of physics and how they apply to the game make this exciting game even more enjoyable to watch.