Doppler Effect

The speed of sound or greater

A sonic boom is an extreme form of the doppler effect. How fast does a plane need to be moving to create a sonic boom?

A cone

A sonic boom is created when a plane is moving so fast that the sound waves in front of it cannot escape at all. What is the shape that these sound waves create?

340m/s

What is the speed of sound?

When the observer and source are moving toward each other.

When does the doppler effect create a higher pitch sound?

When the observer and source are moving away from each other.

When does the doppler effect create a lower pitch sound?

A higher pitch

When sound waves are bunched together in front of a moving ambulance, what does an observer on the ground hear?

A lower pitch

When sound waves are stretched out behind a moving ambulance, what does an observer on the ground hear?

Because sound waves cannot move faster than 340m/s, so the ambulance starts to catch up a little and compresses the sound waves so there is less space between each wave.

Why are sound waves compressed together in front of a moving ambulance?

Because the sound waves are moving backwards at 340m/s and the ambulance is moving forward, so more space is made between each wave.

Why are sound waves stretched out behind a moving ambulance?

Because the sound waves are compressed together

Why does an observer hear a higher pitch in front of a moving ambulance?

Because the sound waves are stretch out

Why does an observer hear a lower pitch behind a moving ambulance?

The sound waves in a sonic boom are in a cone shape with the plain at the point. Where the cone meets the ground is where it can be heard, this is behind the aircraft.

Why is it that when we hear a sonic boom the plane has already passed by?