हिंदी

A Solid Metallic Sphere of Radius 5.6 Cm is Melted and Solid Cones Each of Radius 2.8 Cm and Height 3.2 Cm Are Made. Find the Number of Such Cones Formed. - Mathematics

Advertisements
Advertisements

प्रश्न

A solid metallic sphere of radius 5.6 cm is melted and solid cones each of radius 2.8 cm and height 3.2 cm are made. Find the number of such cones formed. 

संक्षेप में उत्तर

उत्तर

Let the number of such cones formed be n
Now, Volume of solid metallic sphere = Volume of n solid cones

\[\Rightarrow \frac{4}{3} \times \frac{22}{7} \times \left( 5 . 6 \right)^3 = n \times \frac{1}{3} \times \frac{22}{7} \times \left( 2 . 8 \right)^2 \times 3 . 2\]

\[ \Rightarrow 4 \times \left( 5 . 6 \right)^3 = n \times \left( 2 . 8 \right)^2 \times 3 . 2\]

\[ \Rightarrow n = 28\]

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 14: Surface Areas and Volumes - Exercise 14.1 [पृष्ठ २९]

APPEARS IN

आरडी शर्मा Mathematics [English] Class 10
अध्याय 14 Surface Areas and Volumes
Exercise 14.1 | Q 22 | पृष्ठ २९

संबंधित प्रश्न

In one fortnight of a given month, there was a rainfall of 10 cm in a river valley. If the area of the valley is 7280 km2, show that the total rainfall was approximately equivalent to the addition to the normal water of three rivers each 1072 km long, 75 m wide and 3 m deep.


Find the depth of a cylindrical tank of radius 28 m, if its capacity is equal to that of a rectangular tank of size 28 m × 16 m × 11 m.


Find the number of coins, 1.5 cm is diameter and 0.2 cm thick, to be melted to form a right circular cylinder of height 10 cm and diameter 4.5 cm.


The height of a cone is 30 cm. A small cone is cut off at the top by a plane parallel to the base. If its volume be \[\frac{1}{27}\] of the volume of the given cone, then the height above the base at which the section has been made, is


No Question.


A farmer connects a pipe of internal diameter 25 cm from a canal into a cylindrical tank in his field, which is 12 m in diameter and 2.5 m deep. If water flows through the pipe at the rate of 3.6 km/hr, then in how much time will the tank be filled? Also, find the cost of water if the canal department charges at the rate of ₹ 0.07 per m3.


Assertion (A)
The outer surface of a hemisphere of radius 7 cm is to be painted. The total cost of painting at Rs 5 per cm2 is Rs 2300.

Reason (R)
The total surface area of a hemisphere is 3π r2.

  1. Both Assertion (A) and Reason (R) are true and Reason (R) is a correct explanation of Assertion (A).
  2. Both Assertion (A) and Reason (R) are true but Reason (R) is not a correct explanation of Assertion (A).
  3. Assertion (A) is true and Reason (R) is false.
  4. Assertion (A) is false and Reason (R) is true.

Assertion (A)
If the volumes of two spheres are in the ratio 27 : 8, then their surface areas are in the ratio 3 : 2.

Reason (R)
Volume of a sphere `=4/3pi"R"^3`
Surface area of a sphere = 4πR2


  1. Both Assertion (A) and Reason (R) are true and Reason (R) is a correct explanation of Assertion (A).
  2. Both Assertion (A) and Reason (R) are true but Reason (R) is not a correct explanation of Assertion (A).
  3. Assertion (A) is true and Reason (R) is false.
  4. Assertion (A) is false and Reason (R) is true.

A circus tent is cylindrical to a height of 4 m and conical above it. If its diameter is 105 m and its slant height is 40 m, then find the total area of the canvas required.


The surface areas of the six faces of a rectangular solid are 16, 16, 32, 32, 72 and 72 square centimetres. The volume of the solid, in cubic centimetres, is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×