Final answer:
The student's question involves the use of torque and rotational motion principles to find the balance in a pulley system. One applies the concept that net torque must be zero to maintain the system in a state of equilibrium without rotation, and uses formula Τ = r * F to find the necessary forces on pulley cords.
Step-by-step explanation:
The problem relates to torque and rotational motion in physics, specifically within the context of a pulley system. To avoid the rotation of the pulley system when different forces are applied to cords of various radii, one must calculate the balance of torques since the rotational effect depends on both the force applied and the distance from the pivot point (the radius of the pulley). Neglecting friction simplifies the problem as it entails that the net torque must be zero for the pulley to remain stationary (Τnet = 0).
For example, if a smaller flywheel has a cord with a 50 N force applied to it, to find the necessary force for the larger flywheel to keep the system from rotating, we use the torque balance: Τ = r * F, where Τ is the torque, r is the radius, and F is the force. The torques exerted by the forces on each flywheel must be equal and opposite for the pulley to stay still. Therefore, we can set up the equation: 50 N * 0.30 m = F * 0.50 m, and solve for F.