Physics diagram showing a hanging mass connected to a pulley and spinning disk, with labels for tension T, radius r, mass m, angle theta, vertical distance y, and the equation Work = torque * angle.

A vertical mass 𝑚 m hanging from a string The string is wrapped around a small pulley (or a small wheel) of radius 𝑟 r. The small wheel is connected to a larger spinning disk (like a flywheel). The mass drops a vertical distance 𝑦 y and pulls the string, which causes the disk to spin.Draw a clear boundary around just the disk + wheel to show that’s your system. Draw an arrow representing the tension 𝑇 T in the string — that is the external force doing work. Use this to show Work = torque × angle: See more