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

Find the volume (in $cm^3$, rounded off to two decimal places) of a hemispherical cap having a radius of 33.6 cm.

The correct answer is
$25,288.70\pi$

Hemispherical Cap Volume Calculation

We need to calculate the volume of a hemispherical cap with a given radius. The question provides the radius $r = 33.6$ cm. Based on the context and the format of the answer options, it is implied that we need to find the volume of a full hemisphere with this radius.

Hemisphere Volume Formula Explained

The volume of a full sphere is given by the formula $V_{sphere} = \frac{4}{3}\pi r^3$.

A hemisphere is exactly half of a sphere. Therefore, the formula for the volume of a hemisphere ($V_{hemisphere}$) is derived by taking half the volume of the sphere:

$$V_{hemisphere} = \frac{1}{2} \times V_{sphere}$$ $$V_{hemisphere} = \frac{1}{2} \times \frac{4}{3}\pi r^3$$ $$V_{hemisphere} = \frac{2}{3}\pi r^3$$

In this formula, '$r$' represents the radius of the hemisphere.

Step-by-Step Volume Calculation

We are given the radius $r = 33.6$ cm.

First, we need to calculate the cube of the radius, denoted as $r^3$:

$$r^3 = (33.6)^3$$

Let's perform the calculation:

$33.6 \times 33.6 = 1128.96$

$1128.96 \times 33.6 = 37933.056$

So, the value of $r^3$ is $37933.056$ $cm^3$.

Now, we substitute this value into the hemisphere volume formula:

$$V_{hemisphere} = \frac{2}{3}\pi r^3$$

Substituting $r^3 = 37933.056$:

$$V_{hemisphere} = \frac{2}{3}\pi (37933.056)$$

To find the volume, we multiply $37933.056$ by 2:

$$V_{hemisphere} = \frac{2 \times 37933.056}{3}\pi$$ $$V_{hemisphere} = \frac{75866.112}{3}\pi$$

Finally, we divide the result by 3:

$$V_{hemisphere} = 25288.704\pi$$

Rounding the Volume Result

The question asks for the volume to be rounded off to two decimal places.

Rounding the calculated volume $25288.704\pi$ $cm^3$ to two decimal places gives:

$$V_{hemisphere} \approx 25288.70\pi$$

Final Answer Verification

The calculated volume, rounded to two decimal places, is $25,288.70\pi$ $cm^3$. This result matches the value provided in Option 3.

Was this answer helpful?

Important Questions from 3-D Mensuration

  1. Find the total surface area of a closed cylinder having a base radius of 70 m and a height of 110 m. [Use π = \(22\over7\)]

  2. The curved surface area of a cylinder is half of its total surface area. If its height is 195 cm, then find its diameter (in cm).
  3. The diameter of the base and slant height of a right circular cone are 30 cm and 113 cm, respectively. Find the volume (in cm³) of the given cone.
    (Use $\pi = \frac{22}{7}$)

  4. A cylindrical rod has an curved surface area of $4,900 \text{ cm}^2$. If the length of the rod is 97 cm, then the radius (in cm) of the rod, correct to two places of decimal, is:
    Take $\pi = \frac{22}{7}$
  5. The volume (in $m^3$) of a cube, each of whose edges is 42 m, 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