Sound - Speed of Sound - Doppler Effect.

The pitch of a sound wave relates to the wave's _________________.

• Amplitude

• Frequency

• Wavelength

• Period

What is the Doppler Effect?

• A change in frequency due to the relative motion of a wave source and an observer

• When a wave overlaps with another wave

• When a wave bounces off of another object

• When a wave bends due to traveling through a different medium

Tags

NGSS.HS-PS4-1

An ambulance is driving towards you as you stand on the sidewalk. What happens to the pitch of the siren as it comes towards you?

• It increases

• It decreases

Tags

NGSS.HS-PS4-1

You are driving in a car and honk the horn at a person standing in the street. As you approach the person, what happens to the pitch of the horn according to you in the car?

• It increases

• It decreases

• It stays the same because you are in the car moving with the sound.

You are standing on the side of the road when a police car races past you with its siren on. After the police car passes you, what happens to the pitch of the siren?

• It increases

• It decreases

• It turns red

Look at the picture. Who is experiencing a higher pitched sound?

• Observer A

• Observer B

• There's no difference

Tags

NGSS.MS-PS4-1

Look at the picture. Who is experiencing a lower pitched sound?

• Observer A

• Observer B

• There is no difference

Tags

NGSS.MS-PS4-1

A car moves at 20 m/s towards a whistle. The whistle is stationary. The whistle makes a sound with a frequency of 500 Hz. The speed of sound in air on this day is 330 m/s.

What is the frequency observed by the driver of the car?

• 530 Hz

• 470 Hz

• 520 Hz

• 480 Hz

Tags

NGSS.HS-PS4-1

A car moves at 20 m/s away from a whistle. The whistle is stationary. The whistle makes a sound with a frequency of 500 Hz. The speed of sound in air on this day is 330 m/s.

What is the frequency observed by the driver of the car?

• 530 Hz

• 470 Hz

• 520 Hz

• 480 Hz

Tags

NGSS.HS-PS4-1

A fire truck is moving towards you. The fire truck moves with a speed of 30 m/s. You are motionless. The siren on the fire truck makes a sound with a frequency of 700 Hz. The speed of sound in air on this day is 350 m/s.

What frequency will you hear?

• 765 Hz

• 730 Hz

• 660 Hz

• 645 Hz

Tags

NGSS.HS-PS4-1