When a table tennis ball on a thread is made to touch the vibrating prong of a tuning fork the ball swings backwards and forwards. How can this demonstration be used to explain how sound waves are made?

When you see distant streetlights through smog, they look dimmer and redder than they do normally. but when you see the same streetlights through fog or falling snow, they look dimmer but not redder. use your knowledge of the interstellar medium to discuss the relative sizes of the particles in smog, fog, and snowstorms compared to the wavelength of light.