Two masses m and M are connected by a light inextensible string. (One mass is on a ramp of angle theta, and is connected to the other mass by a string going over a pulley and the other mass is hanging straight down) If the surface is frictionless, set up the equations of motion and find the acceleration of the system. My question is this, am I making this too simple? Here's my kinetic energy function. 1/2m(dy/dt)^2 + 1/2M(dy/dt^2) and my potential is mgysin(theta) -Mgy. I'm pretty scatterbrained but it seems to me that there should only be one generalized co-ordinate so that is why I have set my equations up as such. But theres this little nagging part of my brain that says the kinetic energy has two components x and y, but I know energy is a scalar so maybe thats ludicrous. Any help would be appreciated.