How Far Did the Parachutist's Impact Occur from the Swimmer?

AI Thread Summary
A swimmer observes a parachutist's impact and hears the sound twice, once through water and once through air, with a 1.0-second delay. The speeds of sound in air and water are 340 m/s and 1400 m/s, respectively. The problem involves calculating the distance from the swimmer to the splash point using the time it takes for sound to travel through both mediums. The equations derived show that the difference in travel times equals 1 second, leading to a calculated distance of approximately 450 meters. The discussion emphasizes solving the rate x time = distance equation to find the correct distance.
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A swimmer sees a parachutist hit the water and hears the impact twice, once through the water and the second time through the air, 1.0 s later. How far from the swimmer did the impact occur?
Vs air = 340 m/s Vs water = 1400 m/s the answer is 450m

I don't understand what to do :confused:
 
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whatwhat11 said:
A swimmer sees a parachutist hit the water and hears the impact twice, once through the water and the second time through the air, 1.0 s later. How far from the swimmer did the impact occur?
Vs air = 340 m/s Vs water = 1400 m/s the answer is 450m

I don't understand what to do :confused:

This is a straightforward rate x time = distance (r t = d) problem.

Let d = distance from swimmer to splash point.

In terms of d, how much time does the sound take to get from the splash point to the swimmer in air?

In terms of d, how much time does the sound take to get from the splash point to the swimmer in water?

In terms of d, what is the difference between these two times?

(Actually, the answer is not 450m, it's only 449m, but who's counting?)
 
Chestermiller said:
This is a straightforward rate x time = distance (r t = d) problem.

Let d = distance from swimmer to splash point.

In terms of d, how much time does the sound take to get from the splash point to the swimmer in air?

In terms of d, how much time does the sound take to get from the splash point to the swimmer in water?

In terms of d, what is the difference between these two times?

(Actually, the answer is not 450m, it's only 449m, but who's counting?)

Vsound in air= (340)(2)
=680m

V sound in water = (1400)(1)
=1400

1400-680
doesn't equal 450m or 459m
 
whatwhat11 said:
Vsound in air= (340)(2)
=680m

V sound in water = (1400)(1)
=1400

1400-680
doesn't equal 450m or 459m

Hu?

The answer to my first question was: the amount of time it takes for the sound to travel through the air from the splash to the swimmer is d/340 seconds

The answer to my second question was: the amount of time it takes for the sound to travel through the water from the splash to the swimmer is d/1400 seconds

The answer to my third question was: the difference between these two times is (d/340) - (d/1400) =1 second

Are you able to solve this equation for the distance d? If so, what do you get for d?
 

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