badge image

Enroll For Free Now & Improve Your Performance.

×
User Icon
User Icon
User Icon
User Icon
User Icon

Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.
MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Grade: 10

                        

Height of a cone is 60 cm. A small cone is cut off by a plane parallel to the base and it's volume is 1/64 th of the volume of the original cone. The height from the base at which the section is made is?

9 years ago

Answers : (2)

Aman Bansal
592 Points
							

dear akshay,

Let h1 and r1 be the height and radius of the base of the smaller cone and h2 ( = 60 cm ) and r2be the height and radius of the bigger cone. here h1 / h2 = r1 / r2. ( Similar triangles )   ----- ( 1 )

Now according to the question 

( (1 /3 ) pai* r1 2 h1 )  /  (( 1/3) pai * r2 2 h2 )      =1 / 64

r1 2*h1 / r2 2*h2 = 1 / 64         h1 3 /  h2 3  =  1 / 64                  ( by applying relation   1 )

h1 / h = 1 / 4  or h1 / 60  =  1 /  4          ( since h2 = 60 )

or h1 =  15 cm.          There the height from the base at which the section is made =  60 - 15  = 45 cm.Let h1 and r1 be the height and radius of the base of the smaller cone and h2 ( = 60 cm ) and r2be the height and radius of the bigger cone. here h1 / h2 = r1 / r2. ( Similar triangles )   ----- ( 1 )

Now according to the question 

( (1 /3 ) pai* r1 2 h1 )  /  (( 1/3) pai * r2 2 h2 )      =1 / 64

r1 2*h1 / r2 2*h2 = 1 / 64         h1 3 /  h2 3  =  1 / 64                  ( by applying relation   1 )

h1 / h = 1 / 4  or h1 / 60  =  1 /  4          ( since h2 = 60 )

or h1 =  15 cm.          There the height from the base at which the section is made =  60 - 15  = 45 cm.

 BEST OF LUCK..!!!!

We are all IITians and here to help you in your IIT JEE preparation.

Now you can win exciting gifts by answering the questions on Discussion Forum. So help discuss any query on askiitians forum and become an Elite Expert League askiitian.

Now you score 5+15 POINTS by uploading your Pic and Downloading the Askiitians Toolbar : Click here to download the toolbar.. 

AMAN BANSAL

 

9 years ago
R.G. LOKKESH
19 Points
							

dear akshay, Let h1 and r1 be the height and radius of the base of the smaller cone and h2 ( = 60 cm ) and r2be the height and radius of the bigger cone. here h1 / h2 = r1 / r2. ( Similar triangles ) ----- ( 1 ) Now according to the question ( (1 /3 ) pai* r1 2 h1 ) / (( 1/3) pai * r2 2 h2 ) =1 / 64 r1 2*h1 / r2 2*h2 = 1 / 64 h1 3 / h2 3 = 1 / 64 ( by applying relation 1 ) h1 / h2 = 1 / 4 or h1 / 60 = 1 / 4 ( since h2 = 60 ) or h1 = 15 cm. There the height from the base at which the section is made = 60 - 15 = 45 cm.Let h1 and r1 be the height and radius of the base of the smaller cone and h2 ( = 60 cm ) and r2be the height and radius of the bigger cone. here h1 / h2 = r1 / r2. ( Similar triangles ) ----- ( 1 ) Now according to the question ( (1 /3 ) pai* r1 2 h1 ) / (( 1/3) pai * r2 2 h2 ) =1 / 64 r1 2*h1 / r2 2*h2 = 1 / 64 h1 3 / h2 3 = 1 / 64 ( by applying relation 1 ) h1 / h2 = 1 / 4 or h1 / 60 = 1 / 4 ( since h2 = 60 ) or h1 = 15 cm. There the height from the base at which the section is made = 60 - 15 = 45 cm. BEST OF LUCK..!!!! We are all IITians and here to help you in your IIT JEE preparation. Now you can win exciting gifts by answering the questions on Discussion Forum. So help discuss any query on askiitians forum and become an Elite Expert League askiitian. Now you score 5+15 POINTS by uploading your Pic and

9 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies


Course Features

  • 731 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution


Course Features

  • 731 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions


Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details