All Exams Test series for 1 year @ ₹349 only
Question

The Largest possible sphere is carved our of a cube of side 6 cm. What is the volume of the sphere?

The correct answer is

792/7 cm3

Finding the Volume of the Largest Sphere Carved from a Cube

Let's break down this geometry problem step by step. We are given a cube with a side length of 6 cm, and we need to find the volume of the largest possible sphere that can be carved out of it.

Understanding the Relationship Between the Cube and the Sphere

When the largest possible sphere is carved from a cube, the key relationship is that the diameter of the sphere must be equal to the side length of the cube. Any larger sphere would not fit entirely within the cube's boundaries.

  • Side length of the cube = 6 cm
  • Diameter of the largest sphere = Side length of the cube = 6 cm
  • Radius of the sphere = Diameter / 2 = 6 cm / 2 = 3 cm

So, the radius of the sphere is 3 cm.

Calculating the Sphere's Volume

The formula for the volume of a sphere is given by:

\(V = \frac{4}{3}\pi r^3\)

where \(V\) is the volume and \(r\) is the radius. We can use the approximation \(\pi \approx \frac{22}{7}\) as the options are given in fractions involving 7.

Substitute the radius \(r = 3\) cm into the formula:

\(V = \frac{4}{3} \times \frac{22}{7} \times (3 \text{ cm})^3\)

Calculate the cube of the radius:

\((3 \text{ cm})^3 = 3 \times 3 \times 3 \text{ cm}^3 = 27 \text{ cm}^3\)

Now, substitute this back into the volume formula:

\(V = \frac{4}{3} \times \frac{22}{7} \times 27 \text{ cm}^3\)

We can simplify the calculation by cancelling out the 3 in the denominator with the 27:

\(V = 4 \times \frac{22}{7} \times \frac{27}{3} \text{ cm}^3\)

\(V = 4 \times \frac{22}{7} \times 9 \text{ cm}^3\)

Now, multiply the numbers together:

\(V = (4 \times 22 \times 9) \div 7 \text{ cm}^3\)

\(V = (88 \times 9) \div 7 \text{ cm}^3\)

\(V = 792 \div 7 \text{ cm}^3\)

So, the volume of the largest sphere that can be carved from the cube is \(\frac{792}{7}\) cm3.

Dimension Value
Cube Side Length 6 cm
Sphere Diameter 6 cm
Sphere Radius 3 cm
Sphere Volume Formula \(\frac{4}{3}\pi r^3\)
Calculated Volume (\(\pi \approx 22/7\)) \(\frac{792}{7}\) cm3

Comparing with Options

The calculated volume is \(\frac{792}{7}\) cm3, which matches one of the given options.

Volume Calculation Steps Summary

  1. Identify the cube's side length: 6 cm.
  2. Determine the sphere's diameter (equal to the cube's side): 6 cm.
  3. Calculate the sphere's radius (half the diameter): 3 cm.
  4. Use the sphere volume formula: \(V = \frac{4}{3}\pi r^3\).
  5. Substitute \(r=3\) and \(\pi \approx \frac{22}{7}\) into the formula.
  6. Perform the calculation to find the volume.

Revision Table: Cube and Sphere Properties

Shape Key Dimension Volume Formula Relation (Carving Largest Sphere from Cube)
Cube Side Length (\(s\)) \(s^3\) \(s = \) Sphere Diameter
Sphere Radius (\(r\)) \(\frac{4}{3}\pi r^3\) Diameter (\(2r\)) = Cube Side (\(s\))

Additional Information on Carving Shapes

When one shape is carved out of another, the dimensions of the carved shape are limited by the dimensions of the original shape. For carving the largest possible shape, the critical dimensions must match at their limits.

  • Largest cylinder from a cube: The cylinder's diameter and height would both be equal to the cube's side length.
  • Largest cube from a sphere: The vertices of the cube would lie on the sphere's surface. The diagonal of the cube would be equal to the diameter of the sphere.
  • Largest sphere from a cylinder: If the cylinder's height is greater than or equal to its diameter, the sphere's diameter will equal the cylinder's diameter. If the cylinder's height is less than its diameter, the sphere's diameter will equal the cylinder's height.

These relationships are crucial for solving problems involving volumes and dimensions of shapes carved from other shapes.

Was this answer helpful?

Important Questions from Solid Figures

  1. The area of the floor of a cubical room is 192 m 2. The length of the longest rod that can be kept in that room is :

  2. A solid metallic rectangular block of dimensions 112 cm × 44 cm × 25 cm is melted and recast into a cylinder of radius 35 cm. The curved surface area (in cm 2) of the cylinder is: (Take π = 22/7)

  3. If the volume of a cube is 175616 cm 3, what is its side?

  4. The volume of a right circular cone is 1232 cm 3. If the height of the cone is 24 cm, then what will be the radius of its base?

  5. A right triangle contains the right angle between the sides 5 cm and 7 cm. A cone is generated by revolving about the side 5 cm. The volume of this cone is:

Need Expert Advice?

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App