Volume of the Rectangular Solid

Oct 13, 2025 by wbrum.org 14 views

Introduction

In this article, we will explore the concept of finding the volume and surface area of a rectangular solid with given dimensions. The rectangular solid is defined by its length, width, and height, which are expressed as functions of a variable x. We will use these functions to calculate the volume and surface area of the solid.

Given Dimensions

The rectangular solid has the following dimensions:

Length (L): ${$ L = 2x + 5 $}$
Width (W): ${$ W = x - 1 $}$
Height (H): ${$ H = x + 2 $}$

Volume of the Rectangular Solid

The volume of a rectangular solid is given by the formula:

${$ V = L \times W \times H $}$

Substituting the given dimensions, we get:

${$ V = (2x + 5) \times (x - 1) \times (x + 2) $}$

To find the volume, we need to multiply these three expressions together.

Step 1: Multiply the first two expressions

${$ V = (2x + 5) \times (x - 1) $}$

Using the distributive property, we get:

${$ V = 2x^2 - 2x + 5x - 5 $}$

Combining like terms, we get:

${$ V = 2x^2 + 3x - 5 $}$

Step 2: Multiply the result by the third expression

${$ V = (2x^2 + 3x - 5) \times (x + 2) $}$

Using the distributive property, we get:

${$ V = 2x^3 + 4x^2 + 3x^2 + 6x - 5x - 10 $}$

Combining like terms, we get:

${$ V = 2x^3 + 7x^2 + x - 10 $}$

Surface Area of the Rectangular Solid

The surface area of a rectangular solid is given by the formula:

${$ SA = 2(LW + LH + WH) $}$

Substituting the given dimensions, we get:

${$ SA = 2((2x + 5)(x - 1) + (2x + 5)(x + 2) + (x - 1)(x + 2)) $}$

To find the surface area, we need to multiply these three expressions together.

Step 1: Multiply the first two expressions

${$ SA = 2((2x + 5)(x - 1) + (2x + 5)(x + 2)) $}$

Using the distributive property, we get:

${$ SA = 2(2x^2 - 2x + 5x - 5 + 2x^2 + 4x + 5x + 10) $}$

Combining like terms, we get:

${$ SA = 2(4x^2 + 8x + 5) $}$

Simplifying further, we get:

${$ SA = 8x^2 + 16x + 10 $}$

Step 2: Multiply the result by the third expression

${$ SA = (8x^2 + 16x + 10)(x - 1) $}$

Using the distributive property, we get:

${$ SA = 8x^3 - 8x^2 + 16x^2 - 16x + 10x - 10 $}$

Combining like terms, we get:

${$ SA = 8x^3 + 8x^2 - 6x - 10 $}$

Conclusion

In this article, we have found the volume and surface area of a rectangular solid with given dimensions. The volume is given by the formula ${$ V = 2x^3 + 7x^2 + x - 10 $}$, and the surface area is given by the formula ${$ SA = 8x^3 + 8x^2 - 6x - 10 $}$. These formulas can be used to calculate the volume and surface area of the solid for any value of x.

Example Use Cases

Finding the volume of a rectangular solid: If we want to find the volume of the solid when x = 3, we can substitute x = 3 into the formula for volume: ${$ V = 2(3)^3 + 7(3)^2 + 3 - 10 $}$. Evaluating this expression, we get: ${$ V = 54 + 63 + 3 - 10 $}$, which simplifies to ${$ V = 100 $}$.
Finding the surface area of a rectangular solid: If we want to find the surface area of the solid when x = 3, we can substitute x = 3 into the formula for surface area: ${$ SA = 8(3)^3 + 8(3)^2 - 6(3) - 10 $}$. Evaluating this expression, we get: ${$ SA = 216 + 72 - 18 - 10 $}$, which simplifies to ${$ SA = 260 $}$.

Code Implementation

Here is a Python code snippet that calculates the volume and surface area of the rectangular solid:

import sympy as sp

# Define the variable x
x = sp.symbols('x')

# Define the dimensions of the rectangular solid
L = 2*x + 5
W = x - 1
H = x + 2

# Calculate the volume of the rectangular solid
V = L * W * H
V = sp.simplify(V)

# Calculate the surface area of the rectangular solid
SA = 2*(L*W + L*H + W*H)
SA = sp.simplify(SA)

# Print the volume and surface area
print("Volume:", V)
print("Surface Area:", SA)

Q: What is the volume of a rectangular solid?

A: The volume of a rectangular solid is given by the formula ${$ V = L \times W \times H $}$, where L is the length, W is the width, and H is the height of the solid.

Q: How do I find the volume of a rectangular solid with given dimensions?

A: To find the volume of a rectangular solid with given dimensions, you need to multiply the length, width, and height of the solid together. For example, if the length is ${$ L = 2x + 5 $}$, the width is ${$ W = x - 1 $}$, and the height is ${$ H = x + 2 $}$, you can substitute these expressions into the formula for volume: ${$ V = (2x + 5) \times (x - 1) \times (x + 2) $}$.

Q: What is the surface area of a rectangular solid?

A: The surface area of a rectangular solid is given by the formula ${$ SA = 2(LW + LH + WH) $}$, where L is the length, W is the width, and H is the height of the solid.

Q: How do I find the surface area of a rectangular solid with given dimensions?

A: To find the surface area of a rectangular solid with given dimensions, you need to multiply the sum of the products of the length and width, length and height, and width and height of the solid together. For example, if the length is ${$ L = 2x + 5 $}$, the width is ${$ W = x - 1 $}$, and the height is ${$ H = x + 2 $}$, you can substitute these expressions into the formula for surface area: ${$ SA = 2((2x + 5)(x - 1) + (2x + 5)(x + 2) + (x - 1)(x + 2)) $}$.

Q: What is the difference between the volume and surface area of a rectangular solid?

A: The volume of a rectangular solid is the amount of space inside the solid, while the surface area is the amount of space on the surface of the solid.

Q: How do I use the formulas for volume and surface area in real-world applications?

A: The formulas for volume and surface area can be used in a variety of real-world applications, such as:

Architecture: To calculate the volume and surface area of buildings, bridges, and other structures.
Engineering: To calculate the volume and surface area of machines, engines, and other mechanical systems.
Science: To calculate the volume and surface area of molecules, cells, and other biological systems.

Q: What are some common mistakes to avoid when calculating the volume and surface area of a rectangular solid?

A: Some common mistakes to avoid when calculating the volume and surface area of a rectangular solid include:

Not simplifying the expressions: Failing to simplify the expressions for volume and surface area can lead to incorrect results.
Not using the correct formulas: Using the wrong formulas for volume and surface area can lead to incorrect results.
Not checking units: Failing to check units can lead to incorrect results.

Q: How can I verify the accuracy of my calculations for volume and surface area?

A: To verify the accuracy of your calculations for volume and surface area, you can:

Check your work: Double-check your calculations to ensure that you have not made any mistakes.
Use a calculator: Use a calculator to verify your calculations.
Compare with known values: Compare your results with known values to ensure that they are accurate.

Q: What are some real-world examples of rectangular solids and their applications?

A: Some real-world examples of rectangular solids and their applications include:

Boxes: Boxes are rectangular solids used to store and transport goods.
Cubes: Cubes are rectangular solids used in a variety of applications, including architecture and engineering.
Machines: Machines are rectangular solids used in a variety of applications, including manufacturing and transportation.

Q: How can I use the formulas for volume and surface area to solve problems in real-world applications?

A: To use the formulas for volume and surface area to solve problems in real-world applications, you can:

Identify the problem: Identify the problem you want to solve and the relevant formulas.
Apply the formulas: Apply the formulas to the problem and calculate the volume and surface area.
Interpret the results: Interpret the results and use them to solve the problem.