\fdO'^ - Old Forge Coal Mines

184 ELEMENTARY MECHANICS.
(d) Using formula 18,/
sec, = -035995 min., the time of falling
37,500
33,000 X .035995
2X 75
^=i/'t 32.16 = 2.1597
(437) 127 ^62.5 = 2.032 = specific gravity. Ans.
(438)
62.5
1,728
Use i
(439) Use formula 21. W=(^^\
2 X 60X 6.5
or
X .48 = 499.2 lb. Ans. See ^'
6.5-5.75
Fig. 37.
(440)
X 9. 823 = .35529 lb. Ans. ^
See Art. 961.
77., /3 io\ ^^' 1.5X25'
^x(8^^^) = -2-7=^^r32:i6'"^
1.5 X 25'
/r=!^ii!dr' = 406.42 lb. Ans.
f H- 12
(441 ) (a) 2,000 -^ 4 = 500 = wt. of cu.
ft. 500 -j- 62.5 = 8 = specific gravity. Ans.
500 = .28935 lb. Ans.
Fig. 38.
J7
Fig. 37.
m'
(442) See Fig. 38. 14.5 X 2
= 29. 30X 29= J>rx 5, or W^ =
= 30X29 • _ . ., .
5
174 lb. Ans.
(443) 75 X .21 = 15.75 lb.
(444) (a) 900 X 150 = 135,000 ft. -lb. Ans,
= 9,000 ft. -lb. per min. Ans.
135,000
15
(^)A2!E = iH.p
33,000 11
Ans<
2>
Ans.