The document defines key terms related to pendulums, including length, oscillation, equilibrium, amplitude, period, and frequency. Specifically, it states that a pendulum's length is the distance from the point of hanging to the center of the bob, oscillation is the back-and-forth motion around a fixed point as the bob swings from one side to the other and back, and equilibrium is the resting position of the pendulum.

3. The length of a simple
pendulum is the distance
between the point at which it is
hung from the stand and the
centre of the bob.

4. Oscillation is the to and fro motion
of the pendulum about a fixed point.
For example the bob completes one
oscillation when it swings from O to
B, then to A and returns to O.

6. When the pendulum is at
rest ,it is said to be in
equilibrium .The position
of the pendulum at rest is
called equilibrium position.

7. The maximum displacement of
the bob from the equilibrium
position is its amplitude

8. The time taken for one oscillation is
the period
Period =
Time taken for a definite number of oscillation
Number of oscillation
T=n/t

9. Frequency is the number of
oscillations per second
f=n/t