Q7 of 75 Page 236

Find the volume of a sphere whose surface area is 154 cm2

Let the radius be r

Given, Surface area = 154 cm2


4πr2 = 154


4 * * r* r = 154


r = 3.5 cm


Now,


Volume = πr3


= * * (3.5)3


= cm3


More from this chapter

All 75 →
5

How many litres of milk can a hemispherical bowl of diameter 10.5 cm hold?

 6

A hemispherical tank is made up of an iron sheet 1 cm thick. If the inner radius is 1 m, then find the volume of the iron used to make the tank

 8

A dome of a building is in the form of a hemisphere. From inside, it was white-washed at the cost of Rs 498.96. If the cost of white-washing is Rs 2.00 per square meter, find the

(i) Inside surface area of the dome,


(ii) Volume of the air inside the dome

 9

Twenty seven solid iron spheres, each of radius r and surface area S are melted to form a sphere with surface area S′. Find the

(i) Radius r ′ of the new sphere,


(ii) Ratio of S and S′