Question

a seismic wave is traveling through the earth’s mantle. the deeper into the mantle the wave goes, the greater the pressure is. as the pressure in the mantle increases, a. the wave’s speed decreases. b. the wave’s speed increases. c. the wave’s frequency decreases. d. the wave’s frequency increases. earth’s layers image of earths layers: lithosphere, mantle, outer core, inner core reset submit

Explanation:

The question is about seismic waves in the Earth's mantle. Seismic wave speed in a medium is related to the medium's properties, like pressure. As pressure in the mantle increases (deeper into the mantle), the wave speed of seismic waves (like P - waves) generally increases because the mantle material becomes more rigid or dense under higher pressure. Frequency of a wave is determined by the source, not the medium, so options C and D (about frequency) are incorrect. Option A says speed decreases with increasing pressure, which is wrong. So the correct option is B.

Answer:

B. the wave’s speed increases.