05.06.2013 Views

\fdO'^ - Old Forge Coal Mines

\fdO'^ - Old Forge Coal Mines

\fdO'^ - Old Forge Coal Mines

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

ELEMENTARY MECHANICS. 179<br />

The center of gravity of AinnC D E is then at C, , its<br />

geometrical center. ^;« = 4 in. ; angle Bmr— 45^*; there-<br />

A m, B<br />

fore, Br = B7n X sin Bmr = 4: X .707 = 2.828 in. C,, the<br />

2<br />

center of gravity of Bmn, lies on Br^ and B C^ = —Br<br />

o<br />

= 1x2.828 = 1.885 in. BC^ = ABxsm BAC^=Ux<br />

o<br />

sin 45° = 14 X .707 = 9.898 in. C,C, = B C^- B C, = 9.8m<br />

-1.885 = 8.013 in.<br />

4X4<br />

Area ABCDE=W- 2<br />

4X4<br />

= 188 sq. in. Area inBn<br />

= 8 sq. in. Area Amn CDE = 1H8 - 8 = 180<br />

2<br />

sq. in.<br />

The center of gravity of the combined area lies at C, at

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!