An ambulance with its siren on is moving towards an observer. How will the frequency of the siren sound to the observer?

A. Lower than the actual frequency

B. Higher than the actual frequency

C. The same as the actual frequency

D. The frequency will fluctuate rapidly

What phenomenon occurs when an object travels through the air at a speed faster than the speed of sound?

A. Redshift

B. Blueshift

C. Sonic boom

D. Echo

Which of the following is NOT a factor affecting the Doppler Effect for sound?

A. Speed of the source

B. Speed of the observer

C. Frequency of the source

D. Colour of the source

A star is moving away from the Earth. How will its light appear to observers on Earth?

A. Redshifted

B. Blueshifted

C. Unchanged

D. Brighter

What happens to the frequency of a sound wave if both the source and the observer are moving in the same direction at the same speed?

A. Frequency increases

B. Frequency decreases

C. Frequency remains unchanged

D. Frequency fluctuates

a) Explain the principle behind the Doppler Effect, especially in the context of sound waves. [3]

b) A car is moving towards an observer at a speed of 20 m/s. If the car's horn emits a sound of frequency 500 Hz, calculate the frequency heard by the observer. Assume the speed of sound in air is 343 m/s. [3]

a) Describe the difference in the Doppler Effect observed for sound waves and light waves. [3]

b) A distant star is moving away from Earth at a speed of 0.05 times the speed of light. If the emitted light from the star has a frequency of 5 x 10^14 Hz, determine the observed frequency on Earth. [3]

a) What is meant by redshift and blueshift in the context of the Doppler Effect for light? [2]

b) An astronomer observes a galaxy emitting light with a wavelength of 600 nm. If the actual emitted wavelength is 550 nm, is the galaxy moving towards or away from Earth? [3]

a) Define the Doppler Effect and explain how it can be observed in everyday life. [3]

b) A train is moving away from a stationary observer with a speed of 30 m/s. The train blows its whistle, which has a frequency of 400 Hz. Calculate the frequency of the sound heard by the observer. Assume the speed of sound in air is 343 m/s. [3]

c) How would the frequency change if the observer were moving towards the train at a speed of 10 m/s? [3]

a) What is the significance of the Doppler Effect in astronomy? [3]

b) A star is moving towards Earth at a speed of 0.02 times the speed of light. If the emitted light from the star has a frequency of 6 x 10^14 Hz, determine the observed frequency on Earth. [3]

c) Explain the terms "redshift" and "blueshift" in this context. [2]