Fun at the Beach

This past summer, I went to Lanikai Beach with my friends to try to escape the hot summer sun and enjoy the ocean. While at the beautiful beach, my friend took this picture of me jumping off a tiny cliff onto the ground. After looking back at my pictures, I realized that this in fact is Physics also. After I jumped up into the air, my acceleration was -9.8 meters per second squared because I was carried only by gravity. Then, I reached a peak where my velocity was 0 m/s and I stopped going up and began descending down towards the ground at the same accleration of -9.8 meters per second squared. This demonstrates the affect of gravity "g" on acceleration. There was no outside force pushing me down, or pulling me up which is why my acceleration was always -9.8 meters per second squared no matter what direction I was moving. The sign of this value is always negative because even though I am moving in a positive direction, I am slowing down, and when I am moving in the negative direction, I am speeding up. Who knew that my simple jump at the beach could hold so much physics behind it?

Water Park Fun

This summer, my family took a trip to the water park. This picture is another example of velocity, acceleration and position. My brother is lying on a foam mat that slides downhill on the Volcano Express ride. Because it is a steep downhill ride, his velocity is constantly increasing because his speed is constantly increasing. His acceleration is also increasing. However, once he reaches the end of the ride and the slide levels out, his acceleration and velocity will begin to decrease. By the end of the ride, his mat will come to a complete stop and his final velocity will be zero just as his initial velocity was zero when he was at the top of the slide. Therefore, his average acceleration, which is his final velocity minus his initial velocity over the elapased time will be zero.

Wave Boarding

This past weekend, I observed what we are learning in Physics while watching my brother wave board outside our house. In this picture, he is pushing off the ground to begin his motion, giving him a positive velocity and acceleration. Velocity measures his speed and direction. Since his speed is increasing and he is moving forward, his motion would be represented by a straight line with a positive slope on a velocity graph. However, if he were for instance, trying to go up a hill but was unable to and began to slide backwards, his velocity and even his acceleration could be negative because of his change in direction. If my brother started from our house and went down the street, turned around and came straight back to our house using the same route, his total displacement would be 0. This is because he would have travelled about 25 meters forward and negative 25 meters backwards. Since velocity is calculated by dividing the total displacement by the elapsed time, in this case, his average velocity would be 0.