GED Science TestPhysical ScienceMedium
A student is observing a pendulum swinging back and forth. They measure the time it takes for the pendulum to complete one full swing (return to its starting point). What property of the wave-like motion is the student measuring?
- AFrequency
- BPeriod
- CWavelength
- DAmplitude
Show answer & explanationAnswer & explanation
Correct answer: B. Period
The time it takes for one complete cycle or oscillation (like one full swing of a pendulum) is defined as the period of the motion. Frequency is the number of cycles per unit time, amplitude is the maximum displacement, and wavelength applies to propagating waves in space, not just oscillations.
Why the other options are wrong
- A. Frequency is the number of cycles per unit time, the inverse of the period.
- C. Wavelength is the spatial extent of one cycle of a propagating wave, not a time measurement for an oscillation.
- D. Amplitude is the maximum displacement from the equilibrium position, not a time measurement.
Period of Oscillation
The period (T) of an oscillation or wave is the time it takes for one complete cycle or vibration to occur. It is the reciprocal of the frequency.
- Units: seconds (s)
- T = 1/f (Period = 1 / Frequency)
- Represents the duration of one full event (e.g., one swing, one wave)
Memory trick: Period is the 'Time' for a Full Trip