A 20.0-kg block is connected to a 30.0-kg block by a string that passes over a light frictionless pulley. The 30.0-kg block is connected to a spring that has negligible mass and a force constant of 250 N/m as show in the figure. The spring is unstretched when the system is as shown in the figure, and the incline is frictionless. The 20.0- kg block is pulled 20.0 cm down the incline (so that the 30.0-kg block is 40.0 cm above the floor) and released from rest. Find the speed of each block when the 30.0-kg block is 20.0 cm above the floor (that is, when the spring is unstretched).
to 
, a distance of 20.0 m up the incline (and block B drops downward a distance of 20.0 m) if the system starts from rest.
