Chase-durer COMBAT COMMAND GMT Operation Manual - page 8
6.
Miscellaneous
At
68 F
(20 C), sound travels at
344m
or
376yds
/
1,129ft
per second in air at sea level.
°
°
Therefore,
68 F
(20 C) sound
1 mile
(1,760 yards / 5,280 feet) in
1,000 yards
in
1 kilometer
in
To estimate the distance to an event (such as an
explosion, muzzle flash, lightning, etc.), measure
the time from the visual flash to the sound and
multiply the seconds by the per second speed.
For example the measured lightning to thunder
time at
68 F
is
10
seconds.
10
x
344m
or
376yds
/
1,129ft
would produce
3,440m
or
3,760yds
/
11,290ft
. (
2.14miles
)
Alternately, you can divide the measured time at
68 F
by
4.68
to get miles (
10s
/
4.68
=
2.14miles
),
or
2.66
for thousand yard distance, or by
2.91
for
kilometers.
at
will travel:
°
°
°
°
4.68
seconds
2.66
seconds
2.91
seconds
Example:
Sea level temp is
and
lightning to thunder measured time is
18
seconds. Distance of lightning strike point
is:
18s
x
1,129ft
=
20,322ft
18s
x
376yds
=
6,768yds
18s
x
344m
=
6,192meters
OR:
18s
/
4.68s
=
3.85 miles
18s
/
2.66s
=
6.77 thousand yards
18s
/
2.91s
=
6.18 kilometers
68 F
°
At
32
°
F
(0
°
C), sound travels at
332m
or
363yds
/
1,089ft
per second in air at sea level.
Therefore, at
32
°
F
(0
°
C) sound will travel:
1 mile
/ 1,760 yards / 5,280 feet in
1,000 yards
in
1 kilometer
in
4.85
seconds
2.75
seconds
3.01
seconds
NOTE:
30
20
10
31
24
2
4
6
8
0
1
12
14
1
6
1
8
2
0
22
21
23
1
3
5
7
9
1
1
13
15
1
7
1
9
45
15
60
30
CHASE-DURER
COMBAT
COMMAND
AUTOMATIC GMT
9
3
12
6
2
4
6
8
10
12
14
1
6
1
8
2
0
22
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