How and why does a car sound different when it passes you?

It happens when either the source of the waves or the receiver of the waves is moving. The picture shows that the sound waves get compressed as the car moves toward you, creating a higher pitch sound. As the car moves away, the sound waves get spread out and you hear a lower sound.

i think it's 35 meters

the answer is ampere

the ampere is used to measure electricity. an ampere is a unit of electric current equal. a unit of measure for the flow of current in a circuit. one ampere is the amount of current flow provided when one volt of electrical pressure is applied against one ohm of resistance.