Wednesday, January 22, 2020
Physics of Rowing :: physics row boating
Missing Figures "Marathon runners talk about hitting 'the wall' at the twenty-third mile of the race. What rowers confront isn't a wall; it's a hole - an abyss of pain, which opens up in the second minute of the race. Large needles are being driven into your thigh muscles, while your forearms seem to be splitting. Then the pain becomes confused and disorganized, not like the windedness of the runner or the leg burn of the biker but an all-over, savage unpleasantness. As you pass the five-hundred-meter mark, with three-quarters of the race still to row, you realize with dread that you are not going to make it to the finish, but at the same time the idea of letting your teammates down by not rowing your hardest is unthinkable...Therefore, you are going to die. Welcome to this life." -- Ashleigh Teitel The Basics The sport of rowing involves numerous combinations and classes of athletes. Boats can be rowed with or without coxswains (the non-rowing captain) and by 1, 2, 4, or 8 rowers. Each rower can handle one oar (sweeping) or two oars (sculling). Racing shells are currently being made with Carbon or Carbon/Kevlar combinations. The act of rowing involves the transfer of momentum by the rowers and their oars to the water. The momentum is transferred to the water by pulling on the oar and pushing with the legs (the feet are attached to the boat by restraints). This causes the seat to slide backwards and the oars to pivot on the riggers. Each stroke is made up of four basic parts: catch (blade vertical in the water, knees bent, arms forward), drive (legs straight, arms pulling toward the body), finish (oar out of water, blade vertical), recovery (body moves forward, blade turns from vertical to the horizontal). For some of the basic forces acting on a 4+ (coxed four) see Figure 1. Figure 1: mx is the mass for each rower x (1-4) and coxswain (c), M is the mass of the boat, and Fx (x=1- 4) is the force exerted by the stroke and Fdrag is the resistive force of the water. Drag Drag is the transfer of momentum from our moving object to a fluid. A crew moves through both water (in contact with the shell) and air (in contact with a small part of the shell and the rowers). Effect on Crew To minimize air resistance rowers wear skimpy unis and force their coxswains to lay in the very short and narrow stern of the boat.