An explosion occurs at the end of a pier. The sound reaches the other end of the pier by traveling through three media: air, fresh water, and a slender metal handrail. The speeds of sound in air, water, and the handrail are 355, 1410, and 5380 m/s, respectively. The sound travels a distance of 140 m in each medium. (a) After the first sound arrives, how much later does the second sound arrive? (b) After the first sound arrives, how much later does the third sound arrive?

2 answers

t1= s/v1 = 140/355 = 0.394 s.
t2 = s/v2 = 140/1410 = 0.099 s.
t3 =s/v3 = 140/5380 = 0.026 s.
Δt1 =0.099 – 0.026 = 0.073 s.
Δt2 = 0.394 – 0.026 = 0.368 s.
0.073s
0.368s