Q1: The Centre of gravity of a 10 x 15 x 5 cm T section from its bottom, is

ANS:C - 8.75 cm

Horizontal section (flange) = length, 100mm, height 50mm.

Same applies to its vertical section Because the total height of both horizontal and vertical section is 150mm.

Therefore, Horizontal section (A1) = Area, 100 x 50 = 5000mm2, Centroid to bottom = 125mm (i.e.half of 50mm + 100mm),

Vertical section (A2), Area = 100 x 50=5000mm2, centroid to bottom = 50mm (i.e half of 100mm).

Centre of gravity, y = (5000 x 125) + (5000 x 50), i.e. sum of areas x centroid, divided by (5000+5000, i.e.sum of areas), ans = 87.5mm.