An iceboat of mass M = 250 kg sits motionless on a frozen lake. The boat is tied to a stake by a rope of length R = 100 m. A steady wind starts to blow from the West, pushing the boat with a constant force F = 150 N. The boat slides without friction along the ice, moving in a circular arc as the rope stretches taut.

How fast is the boat moving when it reaches the point marked "X"?

Please try to do this problem by breaking the motion of the boat along the arc into a number of little steps; assume that each little step is a short, straight line.