545 OF ENGINEERING FORMULÆ.
To find the Force of the Wind.
V = Velocity of wind in feet per second.
v = Velocity in miles per hour.
P Pressure in lbs. per square foot.
*x — Angle of incidence of direction of the wind with the
plane of the surface when it is oblique.
P =o-002288'V2.
Pa= ’00492 U3.
F = -0023 V2 X sin. x.
Miles per hour. Feet per minute. Feet per second. Force in lbs. per sq. foot
1 88 1-47 •005
2 176 2-93 •020 7
3 264 4-4 •044 f
4 352 5-87 •0J9 i
5 440 7-33 0-123 f
10 880 14-67 0-492 )
15 1320 22 1-107 J
20 mo 29’3 1•968 (
25 2200 36'6 3-075 j
30 2640 41 4-428 )
35 3080 51-3 6-027 J
40 3520 58-6 7-872 )
45 3960 66’0 9-9635
50 4400 73’3 12-300
60 5280 88-0 17-712 1
70 61ÖÜ 102-7 2i-1085
80 7040 117-3 31-488)
100 8800 146’6 49-200 J
Gentle breeze.
Pleasant breeze.
Brisk gale.
High wind.
Hurricane.
Hardly perceptible.
Just perceptible.
Very high wind.
Storm.
Great storm.
Description.
Cyclones.
Direction in the
Northern Hemisphere.
Direction in the
Southern Hemisphere.
Rule for finding the Centro of a Cyclone.—Faeetlio wind ; and about
10 points (112;°, to the right will lie the direction of the centre in the
Nurthern Hemisphere or to tlie left in th« Southern Hemisphere.
2 N