Torsional Pendulum refers to a torsion spring that works by torsion or twisting that is, a flexible elastic object that stores mechanical energy when it is twisted. A torsion pendulum is a mass suspended on a string (or torsion fiber) that rotates periodically. When the mass of a torsion pendulum is rotated from its equilibrium position, the fiber resists the rotation and provides a restoring force that causes the mass to rotate back to its original equilibrium position. When the mass reaches its equilibrium position, it is moving quickly and overshoots.
Torsion Pendulum is a device
consisting of a disk or other body of large moment of inertia mounted on one end of a torsionally flexible elastic rod whose other end is held fixed; if the disk is twisted and released, it will undergo simple harmonic motion, provided the torque in the rod is proportional to the angle of twist.
Example:
Calculate the oscillation period of Torsion Pendulum for the given details.
Length of the Spring 1 = 25 m
Moment of inertia of bob I_{0} = 15kgm^{2}
Torsional Rigidity k_{t} = 10 Nm^{2}
Solution:
Apply Formula:
t = 2pi sqrt (l I_{0} / k_{t})
t = 2*3.14 sqrt (25*15/10)
t = 6.18 sqrt (375/10)
t = 6.18 sqrt (37.5)
t = 6.18*6.12
t = 38.4569889616959 t
Period (t) = 38.4569889616959 t