Question

a right circular cylinder has hemisphere on its both ends.the total height of the solid is 104cm and the radius of two hemisphere is 7cm .find the cost of expenditure to colour its surface ,if the colouring cost is Rs 4per 100msquare
L answer this​

Answer 1

Answer:

Radius of each hemisphere = r = 7cm Height of total solid = 104 c

Height of cylinder, h = 104 - 2× 7 =90cm

Then,

T.S.A. Of the solld = C.S.A. of the cylinder + 2 x C.S.A. of the hemisphere

= 2πrh+ 2 x 2πr²

= 2πr (h+2r)

22 = 2 x x 7(90 + 2 x 7) 7

= 44 x 104

= 4576cm²

= 0.4576m²

..Total surface of the given solid is 0.4576m².

Cost of polish is Rs. 100 per sq. mtr. ..Cost of polishing the solid of area

0.4576m² = 0.4576 x 100 = 45.76

Total cost of polish is Rs. 45.76.