the more the vibration, the lower the pitch.
true
it travels because there are sound waves in the air and they vibrate in your ear.
When air from the lungs is passed over the vocal cords inside the larynx, they vibrate. This makes a sound. The vocal cords are tightened or relaxed to change their length. This changes the speed of vibration which alters the pitch. If only the larynx is involved, the sound comes out as a dull 'aaah' in varying pitch. No recognisable words can be formed without the use of the lips, teeth, tongue and palate. This is why people with serious facial injuries or with many teeth missing often have trouble speaking or being understood.
All forms except a Bose-Einstein condensate, which only occurs at absolute zero.
The heat the side walk absorbs is energy. It makes the atoms in the side walk vibrate as they vibrate more they push away from each other . The more heat(energy). The more they vibrate. the more the side walk expands.