It takes 5 seconds for sound to travel 1 mile through air. It takes only 1 second for sound to travel 1 mile through water. How many minutes faster will a sound 90 miles away travel through water than air?
a.
4 minutes
c.
6 minutes
b.
5 minutes
d.
7 minutes

Question

It takes 5 seconds for sound to travel 1 mile through air. It takes only 1 second for sound to travel 1 mile through water. How many minutes faster will a sound 90 miles away travel through water than air?
a.
4 minutes
c.
6 minutes
b.
5 minutes
d.
7 minutes

dj3strella · Answer

To find how many minutes sooner it would arrive, calculate the 2 times.
d = r*t
t = d/r
In water, r = 1 mi/sec
In air, r = 1/5 mi/sec 
90 miles in air at 0.2 mi/sec --> 90/0.2 = 450 seconds

dj3strella · Answer

so its D