Question

person, lying with ear to the ground, sees a huge stone strike the concrete pavement. A moment later two sounds are heard from the impact: one travels in the air and the other in the concrete, and they are 0.75 s apart. HOw far away did the impact occur

Answer 1

284 m

Step-by-step explanation:

According to engineeringtoolbox(dot)com the speed of compressive sound in concrete is 3700 m/s

The speed of sound in standard air is 343 m/s

If t is the time in seconds of sound travel through the concrete and d is the distance

d = 3700t

d = 343(t + 0.75)

3700t = 343t + 257

3,357t = 257

t = 0.07663 s

d = 3700(0.07663) = 284 m

d = 343(0.07663 + 0.75) = 284 m