Amplitude is represented by which letter: W. What is the frequency of this wave: 3. Wavelength is represented by which letter: X. What is different between these two waves: Amplitude. What is the amplitude of this wave: 1. What is the wavelength of this wave: 2. As energy in a wave INCREASES, the AMPLITUDE___________. : Increases. As energy in a wave INCREASES, the WAVELENGTH ___________. : Decreases . As energy in a wave INCREASES, the FREQUENCY ___________. : Increases. The speed equation for waves is....: Wavelength x Frequency. What is the speed of this wave: 8