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 345, 1410, and 5260 m/s, respectively. The sound travels a distance of 161 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?