Think of the shape of a wave. It looks like a squiggly line. We know the highest part of that line is the peak. The wavelength is the distance between wave peaks. Waves of the same type can differ in wavelength. For example, the wavelength of light waves determines its color. Amplitude is the measurement of a wave's height. It is measured in two ways. Peak-to-peak amplitude is the distance between the peak (the topmost part of a wave) and the trough (the lowermost part). Semi-amplitude is half the peak-to-peak amplitude. Most of the time when people refer to "amplitude," they are referring to the semi-amplitude: the distance from the middle of the wave to the top, or the middle of the wave to the bottom. The amplitude of a sound wave determines its volume. Which of the following best explains the relationship between peak-to-peak amplitude and semi-amplitude?
A Semi-amplitude is half the distance of the peak-to-peak amplitude.
B Semi-amplitude is the same distance as the peak-to-peak amplitude.
C Semi-amplitude is double the distance of the peak-to-peak amplitude.
D Semi-amplitude is always greater than the peak-to-peak amplitude.