Free Fall & Snowboarding jumps

Over spring break I went snowboarding in Oregon with my family. In this picture my brother Ian is in the air after going off a jump. As Ian approached the jump he was going downhill and gaining speed, so his acceleration was negative. When he goes off the jump, Ian has a high initial velocity and he is in free fall, so his new acceleration is -9.8 m/s/s. Ian is moving forward (up), but slowing down so his acceleration is negative. When he gets to the peak of his motion in the air, Ian's velocity will be 0 m/s and then he will start to accelerate again at -9.8 m/s/s, his acceleration is again negative because he is going backward (down) and getting faster. Knowing about acceleration and free fall acceleration can be very important for snowboarders who enjoy spending time in the terrain park. If a snowboarder knows that his or her acceleration will be -9.8 m/s/s after going off a jump, they can clculate how fast they need to be going in order to travel a certain distance in the air and clear any obstacles that might impede a smooth landing. Of course in reality, one's acceleration would be slightly affected by air resistance, however snowboarders are much to rad to worry about inconvenient laws of physics such as this. 

The physics of Kayaking, take 2

This is a picture of me in an ILH kayaking race. As I propel myself though the water with my kayak paddle, I am using two principles of physics, Newton's second and third laws of motion. Newton's second law states that force equals mass times acceleration and his third law states that for every action there is an equal and opposite reaction. To move forward in the kayak, I have to place my paddle in the water and pull backwards, as I pull backwards, I am exerting a force on the water and the water is exerting an opposite force on me. Because the force I applied was backward (or negative), the water exerts a forward ( or positive) force on me, therefore porpelling me forward. Newton's second law allows us to find the acceleration of the kayak bedcause the law states that acceleration is proportional to the force exerted on the object ( the kayak and I), so the harder I pull, the more force I exert, the more force that is inversely exerted on me by the water, and the faster I accelerate. Thus, every time we go out on the beautiful Ala War canal for kayaking practice, the girls and boys on the Iolani kayaking team are using Newton's second and third laws of motion to propel ourselves though the water. 

The Physics of Kayaking