Kayaking

This weekend I had a kayaking race on the Ala Wai Canal. As the race dragged on, I grew tired. I wondered why it seemed so hard to reach the finish line, and then I remembered physics class. The force I was putting in to paddle forward was being countered by the kinetic friction of the water. My kayak would not glide through the water. In the last 100 meters of the race, my boat began taking on water. The mass of my kayak went up, increasing the normal force as well as the kinetic friction that required more force to move the boat at the same acceleration. I also learned that friction from a liquid is different from that of a solid. At a higher velocity in liquid, friction actually increases, compared to friction of a solid where kinetic friction is constant. Luckily for me, the shape of my kayak was streamlined so that less energy was required to push water out of the path of my boat.

Here's a basic diagram showing the forces on my boat. Buoyancy and normal force equals that of weight since my boat did not move in the y coordinate.

Basketball

The other day when I was shooting baskets, I had a new realization for the physics behind it. I would have to shoot the ball at a specific angle and velocity to make the ball land in the hoop. With my release point at 6' 8", the delta y value would have to be 3' 4" while the delta x value would be the horizontal distance to the hoop. Gravity also pulled the ball down at -9.8 m/s2, affecting the time that the ball was in the air. Thank goodness I did not have to literally calculate the exact angle and velocity each time I shot since the body gains a feel for it. I would also have to factor in the equal and opposite force of the ball bouncing off of the backboard on a bank shot.

Here's a game that simulates shooting a basketball with angles, gravity, velocity, and equal and opposite forces.

H.O.R.S.E.
Test your trick shot skills in a freestyle game of basketball Horse.

I'm not in Heaven, but it ain't Hell

Before I knew it, my baseball coach became my AP Physics teacher. Without sugar-coating the difficulty of the course, Doc emphasized the work that would need to be done. Although a little tough now, I know the insane scenarios that he explained to us on the first day are soon to come. Homework is not as much as expected since the concepts of some nights' homework are more easily grasped than others. As the year goes along, I am looking forward to learning about Physics in the lab by discovering in order to understand. I am willing to challenge myself in a hopefully uphill year.





Grading policies have been very fair so far. Tests and quizzes, however, seem to sometimes be do or die since the answer to one problem is used in the next problem and so forth. I have been lucky enough to "do" so far, but whose to say that I won't "die?"





The truth about Physics is that it is more difficult because of the time needed for other subjects. So here is my quick thought for Physics and school as a whole. Summer is long gone.