(2) When the speed of wave increases, why does the frequency of each particle also increases? (I think when speed increases, only the wavelength changes but the frequency should remain constant)
(3) Why infrared radiation is emitted, is it a must for visible light to be emitted at the same time? If they emit at the same time, is it essential for the infrared radiation to be next to the red visible light?
(4) Do all transverse wave and longitudinal wave (no matter in straight or circular pulse) have properties of reflection, refraction, diffraction and interference?
更新1:
May you also answer me this question: If infrared radiation and visible ligh emit at the same time, is it essential for the infrared radiation to be next to the red visible light?