3. Five marks example problems II

1. A funnel consists of a frustum of a cone attached to a cylindrical portion \(12 \ cm\) long attached at the bottom. If the total height be \(20 \ cm\), diameter of the cylindrical portion be \(12 \ cm\) and the diameter of the top of the funnel be \(24 \ cm\). Find the outer surface area of the funnel.

 

Answer:

 

The outer surface area of the funnel \(=\)  \(cm^2\)

 

[Note: Enter the answer upto two decimal places.]

 

 

2. A hemispherical section is cut out from one face of a cubical block (Fig.7.42) such that the diameter l of the hemisphere is equal to side length of the cube. Determine the surface area of the remaining solid.

 

 

Answer:

 

The surface area of the remaining solid \(=\) $\frac{i}{i}\left(i+\mathrm{\pi }\right)i^i$ sq. units