posted by mightymouse .
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 200 N/m. The spring is unstretched when the 30.0 kg block is 20.0 cm above the floor and the incline is frictionless. The 20.0 kg block is pulled 24.0 cm down the incline (so that the 30.0 kg block is 44.0 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).
I'm close to the right answer but I can't find where I messed up in my equation