Q7 of 48 Page 270

A fez, the headgear cap used by the trucks is shaped like the frustum of a cone. If its radius on the open side is 12 cm and radius at the upper base is 5 cm and its slant height is 15 cm, find the area of material used for making it. (π = 3.14)

Given.


Radii of frustum are 12 cm and 5 cm


Slant height is 15 cm


Formula used/Theory.


CSA of frustum is π[R + r] × l


Area of material = CSA of frustum


= π[R + r] × l


= 3.14[12cm + 5cm] × 15cm


= 3.14 × 17cm × 15cm


= 800.7 cm2


More from this chapter

All 48 →
5

A hemispherical tank of radius 2.4 m is full of water. It is connected with a pipe which empties it at the rate of 7 litres per second. How much time will it take to empty the tank completely?

 6

A shuttle cock used for playing badminton has the shape of a frustum of a cone mounted on a hemisphere. The external diameter of the frustum are 5 cm and 2 cm. The height of the entire shuttle cock is 7 cm. Find its external surface area.

 8

A bucket is in the form of a frustum of a cone with capacity of 12308.8 cm3 of water. The radii of the top and bottom circular ends are 20 cm and 12 cm respectively. Find the height of bucket and the cost of making it at the rate of Rs. 10 per cm2.

 9

The volume of sphere with diameter 1 cm is …….. cm3.