Doppler Effect & Sonic Booms

What happens to the wavelength and apparent frequency when the source is moving and continues to emit sound as it travels CLOSER to you?

• Wavelength becomes longer and frequency increases

• Wavelength becomes shorter and frequency increases

• Wavelength becomes longer and frequency decreases

• Wavelength remains the same and frequency increases

What happens to the frequency perceived by an observer moving away from the source?

• Frequency becomes zero

• Frequency increases

• Frequency remains the same

• Frequency decreases

What happens to the frequency perceived when the relative motion of source and observer is toward one another?

• Frequency becomes zero

• Frequency increases

• Frequency remains the same

• Frequency decreases

What happens to the pressures in the sonic boom when the aircraft flies close by at low altitude?

• Pressures decrease

• Pressures remain the same

• Pressures become destructive

• Pressures increase

What is the result of the constructive interference of sound created by an object moving faster than sound?

• Sonic boom

• Shock wave

• Ultrasonic waves

• Infrasonic waves

When the car moves AWAY from you, its horn seems...

• Low pitched
• High pitched
• Normal

When an ambulance move TOWARD you it sounds ________ pitched. 

• high
• low
• medium

What can you tell about this object's motion?

• Moving to the North (up).
• Moving to the South (down). 
• Moving to the West (left). 
• Moving to the East (right). 

What can you tell about the motion of this object?

• Moving left.
• Moving right quickly.
• Standing still. 
• Moving up slowly. 

A sound with a low frequency produces a

• high pitch

• loud sound

• low pitch

• low sound