(Q11).A wooden article was made by scooping out a hemisphere from each end of a solid cylinder, as shown in the figure. If the height of the cylinder is 10 cm and its base radius is of 3.5 cm, find the total surface area of the article.

Answer:

Surface area of the given solid = C.S.A. of the cylinder + 2 × C.S.A. of hemisphere.

If we take base = radius

Cylinder:

Radius (r) = 3.5 cm

Height (h) = 10 cm

C.S.A. = 2πrh

= cm²

Hemisphere:

Radius (r) = 3.5 cm

C.S.A. = 2πr²

= cm²

2 × C.S.A. = × = cm²

∴ T.S.A. = + = cm².