English

Find the Volume of a Right Circular Cone With: Height 21 Cm and Slant Height 28 Cm. - Mathematics

Advertisements
Advertisements

Question

Find the volume of a right circular cone with: 

height 21 cm and slant height 28 cm. 

Solution

From the relation 

`l^2=r^2+h^2,`we have  

`r=sqrt(l^2-h^2)=sqrt((28)^2)-(21)^2=7sqrt7cm`  

So, volume of cone =`1/3xxpir^2xxh` 

`=1/3xx22/7xx(21)^2xx(7sqrt7)^2` 

`=7546cm^3`

shaalaa.com
  Is there an error in this question or solution?
Chapter 20: Surface Areas and Volume of A Right Circular Cone - Exercise 20.2 [Page 20]

APPEARS IN

RD Sharma Mathematics [English] Class 9
Chapter 20 Surface Areas and Volume of A Right Circular Cone
Exercise 20.2 | Q 1.3 | Page 20

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Find the ratio of the curved surface areas of two cones if their diameters of the bases are equal and slant heights are in the ratio 4 : 3.  

 


Two cones have their heights in the ratio 1 : 3 and the radii of their bases in the ratio 3 : 1. Find the ratio of their volumes. 


A heap of wheat is in the form of a cone of diameter 9 m and height 3.5 m. Find its volume. How much canvas cloth is required to just cover the heap? (Use ЁЭЬЛ = 3.14). 


A conical pit of top diameter 3.5 m is 12 m deep. What is its capacity in kilo litres? 

 


The cross-section of a railway tunnel is a rectangle 6 m broad and 8 m high surmounted by a semi-circle as shown in the figure. The tunnel is 35 m long. Find the cost of plastering the internal surface of the tunnel (excluding the floor) at the rate of Rs. 2.25 per m2.


A solid is in the form of a right circular cone mounted on a hemisphere. The diameter of the base of the cone, which exactly coincides with hemisphere, is 7 cm and its height is 8 cm. The solid is placed in a cylindrical vessel of internal radius 7 cm and height 10 cm. How much water, in cm3, will be required to fill the vessel completely?


Surface area of a cone is 188.4 sq.cm and its slant height is 10 cm. Find its perpendicular height ( π= 3.14)


The curved surface area of a right circular cone of radius 11.3 cm is 710 cm2. What is the slant height of the cone ? 


The volume of a conical tent is 1232 m3 and the area of the base floor is 154 m2. Calculate the: height of the tent.


The surface area of a solid sphere is increased by 21% without changing its shape. Find the percentage increase in its: volume


Share
Notifications

Englishрд╣рд┐рдВрджреАрдорд░рд╛рдареА


      Forgot password?
Use app×