(Q5).A medicine capsule is in the shape of a cylinder with two hemispheres stuck to each of its ends. The length of the capsule is 14 mm and the width is 5 mm. Find its surface area.

Answer:

14mm5mm

Surface area of the capsule = C.S.A. of 2 hemispheres + C.S.A. of the cylinder

i) Now for Hemisphere:

Radius (r) =
d
2
 =
= mm

C.S.A of each hemisphere = 2πr2

C.S.A of two hemispheres

= × 2πr2 = πr

= ×
×
×
=

= mm2.

ii) Now for Cylinder:

Length of capsule = AB =14 mm

Then height (length) cylinder part = – ()

h = – = mm

Radius of cylinder part (r) =

Now C.S.A of cylinder part = 2πrh

= ×
×
×
=

= mm2

Now total surface area of capsule

= + = mm2