Which of the following will cause a change in pitch when a sound is approaching or receding?
absolute magnitude
doppler shift
emission spectrum
parallax

Doppler shift

Explanation:

Doppler effect an be defined as the change in the sound waves frequency, pitch or wavelength due to the movement that is relative to the wave sound. It can be observed when a sound is approaching or receding an observer.

When any sound is far from the ear then its sound is low and when it reaches the ear its volume increases as the pitch increases.

The change in the frequency of the sound is due to Doppler's Effect.

weathering - colorado river carves land in arizona to form the grand canyon. cracks form in a sandstone wall surrounding a house. a marble statue near the science museum is changing color due to rainfall

erosion - after a rainstorm, soil and rock piees litter the roadways. the sand dunes in the sahara desert are changing shape.

here's your answer.