A solid sphere, a hollow spherical shell, a solid cylinder, and a thin cylindrical ring, all having identical mass and outer radius, are released simultaneously from rest at the top of an inclined plane to roll down without slipping. Which of these objects reaches the bottom of the incline first?

💡 Solution & Explanation

The object with the smallest moment of inertia relative to its mass and radius partitions less potential energy into rotational kinetic energy, leaving more available for translational kinetic energy and resulting in higher linear acceleration. A solid sphere possesses the lowest moment of inertia coefficient among standard symmetrical rigid bodies, allowing it to complete the descent ahead of all others. Rings and hollow shells have higher inertia coefficients that retard their acceleration down the incline. Rolling without slipping ensures that static friction does no net work on the system.