Answer:
s = 1800 m = 1.8 km
Explanation:
The distance, the speed, and the time of reach of the sound are related by the following formula:
[tex]s = vt[/tex]
where,
s = distance
v = speed
t = time
FOR WATER:
[tex]s = v_wt[/tex] ---------------------- eq (1)
where,
s = distance between ship and diver = ?
[tex]v_w[/tex] = speed of sound in water = 1440 m/s
t = time taken by sound in water
FOR AIR:
[tex]s = v_a(t+4\ s)[/tex] ---------------------- eq (2)
where,
s = distance between ship and diver = ?
[tex]v_a[/tex] = speed of sound in water = 344 m/s
t + 4 s = time taken by sound in water
Comparing eq (1) and eq (2),because distance remains constant:
[tex]v_wt=v_a(t+4\ s)\\\\(1440\ m/s)t = (344\ m/s)(t+4\ s)\\(1440\ m/s - 344\ m/s)t=1376\ m\\t = \frac{1376\ m}{1096\ m/s}[/tex]
t = 1.25 s
Now using this value in eq (1):
[tex]s = (1440\ m/s)(1.25\ s)[/tex]
s = 1800 m = 1.8 km