An Atwood machine consists of two masses (m1 = 225 grams, m2 = 385 grams) connected by a string over a frictionless pulley. The initial heights above the floor are H1 = 172 cm and H2 = 246 cm. Both masses start from rest at point A in the position shown; point B is just as m2 hits the floor. The total mechanical energyin the system is 13.1. what is the kinetic energy of the system at point b?