\fdO'^ - Old Forge Coal Mines

218 STRENGTH OF MATERIALS.
n o. I// 38,000 X 56.945
Hence, 2AIV=
^ ^ ^^^^
'^
.
38,000 X 56.945 _
24X6X3.25 -*'^^*^^- ^^s.
(581) {^) From the table of Bending Moments,
From formula 74,
«;Xl92' _5y
^'^- '
8 -A'
5, = 7,200;/=8; 7=1^^^ = ^; ^ = 1-^=5.
Then
jf; =
^^ X 192' ^ 7,200 ^^ 2,000
7,200 X 2,000 X 8
8 X 12 X 5 X 192 X 192
12 X 5
6.51 lb. per in. = 6.51 X 12 = 78.12 lb. per ft. Ans.
/A\ r
1 A ^3 10 X 2" 80 ,^
w X 192' _ 7,200
80
8 8 12 X 1
7,200 X 80 X 8 . ^ ,,
w = -—^— -— —- = 1.3 lb. per m.
8 X 12 X 192 X 192
= 1.3 X 12 = 15.6 lb. per ft. Ans.
(582) {(t) From the table of Bending Moments, the
K T///S
deflection of a beam uniformly loaded is —— ^ , . In
384 Ji I
Example 579, W= 874 X 20 = 17,480 lb.; /= 240', E =
25,000,000, and 7=280.
XX A a ^' 5X 17,480 X 240' . . ,^
Hence, deflection s = 77-7^—
^- = \,.r. r.,^r.—^t7T7: -45 m. Ans.
'
^
384 X 20,000,000 X 280
1 IfV
{b) From the table of Bending Moments, s = — ^ , .