Atwood Machine — Pulley Tension & Acceleration (3D)

This is a genuine three-dimensional rebuild of the 2D Atwood machine: two masses connected by a string over a pulley, viewed with a real orbitable camera instead of a flat side view. The physics is ported over unchanged — a = (m1 − m2)g / (m1 + m2 + I_p/R²) for the net acceleration, and T1 = m1(g − a), T2 = m2(g + a) for the string tension on each side — so a real pulley moment of inertia I_p still splits the tension exactly as it does in the 2D version. What the extra dimension adds is depth: the pulley's spokes visibly spin up around a real axle, the two mass cubes recede and approach as you orbit around the rig, and the ceiling bracket and floor grid give the scene genuine spatial context that a 2D side view cannot.