If we have an Atwood machine that has two masses, $M_1$ and $M_2$, where $M_2$ is laying flat on a table and $M_1$ is suspended by a rope connected through a pully to $M1$. The pulley can rotate, and for the sake of my question, there is no internal friction in the pulley. The table is frictionless as well.
Here is a quick diagram:
I tried to attempt to find all the forces, but what stumped me is what would be the effect of $M_1$ to the pulley. If we release the system, then $M_2$ will provide a force of gravity and thus create a torque on the pully. Because surface of the table is frictionless, there doesn't seem to be any force done by $M_1$ because of Newton's 3rd law. If the pulley was a point particle that had no effect on the system (and so no torque), I can easily see that $M_1$ moves because of $M_2$. When we go back to our original question at hand, even if $M_2$ moves $M_1$, how would $M_1$ end up affecting the pulley. I'm quite lost and I'm assuming this goes against my intuition of real life- that is with friction.