Question

the hammering on a train track is often heard twice by workers farther down the track; first as the sound travels through the steel and second as the sound travels through the air. this suggests which graph is true? a b c d

Explanation:

Step1: Recall sound - speed property

Sound travels faster through solids (like steel) than through gases (like air).

Step2: Analyze graphs

We need a graph where the speed of sound in steel is higher than the speed of sound in air.

Answer:

There is no complete graph information for options C and D in the provided content. But among options A and B, option A shows the speed of sound in steel lower than in air, and option B shows the speed of sound in steel and air as equal. Since sound travels faster in steel than in air, if we assume the correct - type graph is among the complete ones, the correct graph should show a higher bar for steel compared to air. Without full information on C and D, we can't give a definite multiple - choice answer. If we had to choose from A and B, neither is correct as per the physical property of sound speed. But if we consider the principle, we expect a graph with a higher speed value for steel than air.