PHYSICS! HELP ME PLEASE ASAP! 1.) If an ambulance passes you while you're walking your dog, a change in pitch is ?
A.) not perceived by either the pedestrian or you
B.) perceived by the you
C.) perceived by the driver

2.) In the star wars movies, the soundtrack is very important. musicians and sound technicians spend weeks perfecting the noise of the light sabers, lasers, tie fighters and explosions. in real life, there would be no sound at all in space. Why?
A.) mechanical waves require a medium to travel
B.) sound is an electromagnetic wave
C.) mechanical waves do not require a medium to travel
D.) sound is a product of vibration

3.) what is a compression?
A.) region of zero pressure in a medium caused by a wave passing
B.)region of a high altitude in a medium caused by a passing wave
C.) region of a high pressure in a medium cause by a passing wave
D.) region of low pressure in a medium caused by a passing wave