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.