Question

spsule is in the shape of a
o hemispheres stuck to each
ee Fig. 15.10). The length of
ule is 14 mm and the diameter
is 5 mm. Find its surface area.

Answer 1

LSA of cylinder = 2πrh = 2(22/7)(5/2)(14-[(5/2)+(5/2)])
=110/7(9)
=990/7
CSA of each hemisphere = 2πr² = 2(22/7)(5/2)(5/2)
=275/7
Therefore, surface area of the capsule = LSA of cylinder + 2(CSA of hemispheres)
=(990/7)+2(275/7)
=(990/7)+(550/7)
=1540/7
=220 mm².
∴ Surface area of the capsule = 220 mm² .

Answer 2

diameter of capsule=5mm
radius of capsule=5÷2=2.5mm
radius of both hemisphere=2.5mm
Total height of capsule=14mm
height of cylindrical part=14-(2×2.5)[because there r two hemispheres]
=14-5=9mm
Surface area of capsule=curved surface area of cylinder+2×curved surface area of hemisphere
=2πrh+2×2πr^2
=2×22÷7×2.5×9+2×2×22÷7×(2.5)^2
=990÷7+550÷7
=(990+550)÷7
=1540÷7
=220mm^2