Trig type question -- Speed of sound in water and in air

[classicswiss]

Homework Statement

An explosion occurs on the surface of a lake, and the explosion is felt some distance from the site or origin by a hydrophone below the water and by a microphone in air directly above the microphone. Taking the speed of sound in air to be 343m/s and the speed of sound in water to be 1,500 and a delay of 0.3 seconds between both the hydrophone and microphone receiving it, how far is the hydrophone from the explosion?

Relevant Equations

speed= distance / time

unsure

 

[haruspex]

Homework Statement:: An explosion occurs on the surface of a lake, and the explosion is felt some distance from the site or origin by a hydrophone below the water and by a microphone in air directly above the microphone. Taking the speed of sound in air to be 343m/s and the speed of sound in water to be 1,500 and a delay of 0.3 seconds between both the hydrophone and microphone receiving it, how far is the hydrophone from the explosion?
Relevant Equations:: unsure

unsure

It's a question about distances speeds and times. If you've not encountered any relevant equations for that combo your education is sorely lacking.

Per forum rules , you must show some attempt.

 

[Delta2]

If we assume that the phrase "directly above the hydrophone" means that the vertical distance between the hydrophone and the microphone is negligible, then it is a simple linear (first degree) equation you have to solve to answer this.
Assume $x$ is the distance of the hydrophone from the explosion and $t=0$ is the time that the explosion happens. Try to answer the following two questions (answer will be in terms of $x$ and the speed of sound in water and/or in air)

1. After how much time $t_1$ the microphone picks the sound ,
2. After how much time $t_2$ the hydrophone picks the sound.

It is given that $t_1-t_2=0.3$ so if you answer the above two questions, you can plug the expressions of $t_1$ and $t_2$ in the latter equation and solve for $x$.