A laser that produces a spot of light that is 1.25 mm in diameter is shone perpendicularly on the center of a thin, perfectly reflecting circular (2 mm in diameter) aluminum plate mounted vertically on a flat piece of cork that floats on the surface of the water in a large beaker. The mass of this "sailboat" is 0.25 g, and it travels 1.7 mm in 75.0 s. Assuming that the laser power is constant in the region where the sailboat is located during its motion, what is the power of the laser? (Neglect air resistance and the viscosity of water.