Question -
Answer -
(i) Cost ofwhite-washing the dome from inside = Rs 4989.60
Cost of white-washing1m2 area = Rs 20
CSA of the inner sideof dome = 498.96/2 m2 = 249.48 m2
(ii) Let the innerradius of the hemispherical dome be r.
CSA of inner side ofdome = 249.48 m2 (from (i))
Formula to find CSA ofa hemi sphere = 2πr2
2πr2 =249.48
2×(22/7)×r2 =249.48
r2 =(249.48×7)/(2×22)
r2 =39.69
r = 6.3
So, radius is 6.3 m
Volume of air insidethe dome = Volume of hemispherical dome
Using formula, volumeof the hemisphere = 2/3 πr3
=(2/3)×(22/7)×6.3×6.3×6.3
= 523.908
= 523.9(approx.)
Volume of airinside the dome is 523.9 m3.