This Sunday, justin was riding erin's bike around her neighborhood exploring the different streets of kapahulu. He had already gone down the other end of the street, but was reluctant to climb the mountain at the other end a little afraid he couldn't handle it without walking the bike up the hill. He remembered he was a man and could do anything so he contemplated whether it would be easier to go straight up or to gradually zig-zag up the hill. Because of physics class, i already knew the answer, but said nothing when justin said he would find out which technique would require less work. As a result, he experimented and went up twice both ways. The first time he went up the hill somewhat quickly, but looked quite winded at the top and took him a while to come back down as he caught his breath. As he neared the top of the hill, he could feel the potential energy building as it got harder and harder to peddle. When he rolled down the hill i noticed his kinetic energy was building and potential energy was decreasing. The second time he zig-zagged up and it seemed to be a lot easier and less strenuous, although it took him forever to get up. He realized, if he used more energy to get up the hill, he took less time, but when he put in less energy, he took longer to get up the hill. So justin learned today that either way he went up the hill he put in the same amount of work.
I just realized that whenever I catch a wave i am demonstrating physics. When i am floating on the water, i am, for the most part, a stationary object. My velocity is zero meters per second. The wave approaching me is traveling at a certain velocity and if this is an example of a sticky collision, it has a mass too. After I catch the wave, i have the same velocity as the wave, assuming i am riding the wave straight forward. To find the final velocity of the wave and i the equation for a sticky collision is mass of the wave times the velocity of the wave plus the mass of me times my velocity equals my mass plus the waves mass, times the final velocity. In a sticky collision, the my momentum before i caught the wave plus the momentum of the wave is conserved and equals the same momentum of me and the wave after the collision. I am sure a wave is not a good example since it probably does not slow down when it collides with me as it is related to the wind and tide and would have an ambiguous mass, but it reminded me of the concept of sticky collisions.
