Question

A blue whale makes a call underwater at the same time as an elephant calls on land. How long will it take each of these sounds to travel 3 km

Answer 1

 sound in water=4.3 speed of sound in air ( = 343.2 m/s) at 20 deg.C

Answer 2

of we take sound V as 343m/s the elephant will take 8.75sec.
and in the water the sound V is 1493m/s the whale will take 2.01sec.