Question

A sonar device on a submarine sends out a signal and receives an echo `5 s` later. Calculate the speed of sound in water if the distance of the object from the submarine is `3625 m`,

Answer 1

The time taken by the ultrasound signal sent by sonar device to travel from the submarine to the object, and back to the submarine (in the form of an acho) is 5 seconds. So, the time taken by ultrasound signal to travel from the submarine to the object will be half this time, which is `(5)/(2) = 2.5` seconds. This means that the sound takes 2.5 seconds to travel from the submarine to the object in sea water.
Now, Speed `= ("Distance")/("Time")`
Speed `=(3625m)/(2.5s)`
Speed `= 1450 m//s`
Thus, the speed of sound in sea water is `1450 m//s`.