Type of pendulum: small oscillations of a suspended rigid body under gravity A rigid body is suspended vertically and oscillates with a small amplitude due to gravity. Identify the correct term for this system.

Concept/Approach
A compound (physical) pendulum is any rigid body oscillating about a horizontal axis under gravity. A simple pendulum is an idealized point mass on a massless string. A torsional pendulum oscillates by twisting a wire (restoring torque), not by gravity about a pivot. A second's pendulum specifically has a 2 s period.

Final Answer
compound pendulum