Help with science/mathematical problem?

Question

I'm doing a lab assignment for my Oceanography class, but I'm horrible at math, so I want to put this out there to see if someone can tell me if I'm going at this the right way (or not).

Here's the problem:

At a sound velocity of 1450 meters/second (800 fathoms/second), how long would it take a sound pulse from a ship directly over a canyon 3000 meters deep to go from the ship to the bottom and return?

Answer in seconds.

Okay - so the formula is D = V x T

I have V = 1450, D = 3000, right?

Since the sound pulse has to go down 3000 feet and back up, then that would be 6000 feet wouldn't it?

So since I am searching for T, wouldn't I divide 6000 by 1450?

I get a decimal - I would think I'd come out with an even number.

I'm hopeless, I'm afraid. Please be nice to me. I'm an Arts major and have never been good with science or math.

Thank you so much for any help you can give me.

Answer 1

You are right you do divide Distance by Velocity.  Travelling to the bottom and back would be 6000 ft.  6000 ft / 1450 ft/sec = 4.14 sec

You did a great job!

Answer 2

You did it right, although your explanation of how to do it is somewhat more complex than it could be, but it is correct, and yes, you do get decimals...

Canyon is 3000 m deep - thus, the sound has to go 3000m down and again 3000m up to return. So, the total distance is 6000m.

If it goes 1450 m/s then the time needed will be 6000/1450 = 4.1379 seconds and a few more digits after that.

If you think it'd come out with an even number, here's a simplified version:

Total distance = 6000 meters.

Based on speed of 1450 m/s, first 1450 meters will take 1 second. Then, next 1450 meters (for the total of 2900) will be another second (total of 2 seconds). Keep adding chunks of 1450 meters and you will get 4 such chunks, total 5800 meters, for the total of 4 seconds.

And now you still have 200 meters to go, at the speed of 1450 m/sec, and that part makes the decimal part of your result.