UNIVERSE
PLANETARY INTERIORS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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A wave’s speed changes as the wave passes through different materials.
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They tell us nothing
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This speed change results in the wave changing its direction of travel.
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They move the earth in different directions so we know how earth’s interior is because the layers move individually
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Detailed explanation-1: -Seismic waves travel at different speeds through different materials. In this 2-layer model two wave fronts leave an impact at the same time but the lower layer is faster. Seismic waves travel a curving path through the earth due to changes in composition, pressure, and temperature within the layers of the Earth.
Detailed explanation-2: -Seismic waves travel more quickly through denser materials and therefore generally travel more quickly with depth. Anomalously hot areas slow down seismic waves. Seismic waves move more slowly through a liquid than a solid.
Detailed explanation-3: -Refraction. All types of waves change speed and direction when they pass through different materials including seismic waves. This phenomenon is called refraction. That is what makes light focus in a magnifying glass, and refraction is also what makes seismic waves travel in curved paths through the Earth.