Question

the three objects shown here all have the same mass and the same outer radius. each object is rotating about its axis of symmetry (shown in blue). all three objects have the same rotational kinetic energy. which object is rotating fastest?

Answer 1

The solid cylinder is rotating fastest among the three objects.

Step-by-step explanation:

The object that is rotating fastest among the three objects with the same mass and outer radius is the solid cylinder. Since all three objects have the same rotational kinetic energy, the object with the smaller moment of inertia will have a larger angular velocity. The solid cylinder has the smallest moment of inertia compared to the hollow cylinder and the disk, allowing it to rotate fastest.