When the amplitude of a wave decreases while maintaining the frequency, the speed and wavelength of the wave remain unaffected. The speed of a wave is determined by the properties of the medium through which it propagates and is not dependent on the amplitude of the wave. Therefore, decreasing the amplitude of a wave does not change its speed.
Similarly, the wavelength of a wave is related to its speed and frequency through the equation:
λ = v / f
where λ represents the wavelength, v represents the speed of the wave, and f represents the frequency of the wave. Since the speed of the wave remains constant and the frequency is maintained, the wavelength will also remain unchanged.
In summary, decreasing the amplitude of a wave while maintaining the frequency will not alter the wave's speed or wavelength. The amplitude solely affects the intensity or magnitude of the wave, while the speed and wavelength are determined by the properties of the medium and the frequency of the wave.