Surface Area of a Hemisphere

Vinayak got a playing top (lattu) as his birthday present which surprisingly had no colour on it. He wanted to colour it with his crayons. The top is shaped like a cone surmounted by a hemisphere. The entire top is $5 \mathrm{c}\mathrm{m}$ in height and the diameter of the top is $3.5 \mathrm{c}\mathrm{m}$. Find the area he has to colour.

A hemispherical dome of a building needs to be painted. If the circumference of the base of the dome is $17.6 \mathrm{m},$ find the cost of painting it. Given the cost of painting is $\mathrm{₹} 5 \mathrm{p}\mathrm{e}r 100 \mathrm{c}{\mathrm{m}}^2$.

If the total surface area of a solid hemisphere is $27 {\mathrm{cm}}^2$, then its radius is:

Assume $\mathrm{\pi }=\frac{22}{7}$, unless stated otherwise.

A dome of a building is in the form of a hemisphere. From inside, it was white-washed at the cost of $₹498.96$. If the cost of white-washing is $₹2.00 \mathrm{per} \mathrm{square} \mathrm{meter}$, and the inside surface area of the dome is $k {\mathrm{m}}^2$, find $k$.

A hemispherical bowl is made of steel, $0.25 \mathrm{cm}$ thick. The inner radius of the bowl is $5 \mathrm{cm}$. Find the outer curved surface area of the bowl.

A right circular cylinder just encloses a sphere of radius $r$ (see fig). Find ratio of the areas of the sphere and curved surface area of the cylinder.

A right circular cylinder just encloses a sphere of radius $r$ (see fig). Find curved surface area of the cylinder.

A right circular cylinder just encloses a sphere of radius $r$ (see fig). Find surface area of the sphere.

The diameter of the moon is approximately one-fourth of the diameter of the earth. Find the ratio of their surface areas.

Find the radius of a sphere whose surface area is $154 {\mathrm{cm}}^2.$

A hemispherical bowl made to brass has inner diameter $10.5 \mathrm{cm}$. Find the cost$\left(\mathrm{in} ₹\right)$ of tin-plating it on the inside at the rate of $₹16 \mathrm{per} 100 {\mathrm{cm}}^2$. ($\mathrm{\pi }=\frac{22}{7}$)