Vocabulary
- Accelerometer: an instrument for measuring acceleration, typically that of an automobile, ship, aircraft, or spacecraft
- Amplitude: the maximum displacement of bob from the equilibrium
- Bob: a mass attached to the end of a pendulum
- Equilibrium: a pendulum's resting position
- Frequency: number of cycles, or periods, per second
- Oscillation: swinging; moving back and forth between two points
![Picture](/uploads/2/2/8/9/22893520/1899658.png)
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- Period (of a pendulum): time required for a pendulum to complete one full oscillation. The formula for determining the period (T) is on the right; it is defined in terms of gravity (g) and the pendulum's length (L).
![Picture](/uploads/2/2/8/9/22893520/4462300.png)
- Periodic motion: a simple repetitive motion which begins at the starting point (a), passes through the equilibrium (b) and reaches the opposite point (c)
- Seismometer: a detecting device that measures the direction, intensity, and duration of earthquakes