Examples with solutions for Cubes: Using a formula to calculate volume

Exercise #1

The area of the cube is 486.

Calculate the length of the side of the cube and its volume.

S=486S=486S=486aaa

Video Solution

Step-by-Step Solution

Let's solve this problem step-by-step:

Step 1: Given the surface area S=486 S = 486 , we know the formula for the surface area of a cube is:

  • S=6a2 S = 6a^2

Step 2: We need to rearrange this formula to find a a . The equation becomes:

  • a2=S6 a^2 = \frac{S}{6}
  • a=S6 a = \sqrt{\frac{S}{6}}

Step 3: Substitute the given surface area into this equation:

a=4866 a = \sqrt{\frac{486}{6}}

Step 4: Perform the division:

a=81 a = \sqrt{81}

Step 5: Calculate the square root:

a=9 a = 9

Now that we have found the side length, let's find the volume:

Step 6: Use the formula for the volume of a cube:

  • V=a3 V = a^3

Step 7: Substitute a=9 a = 9 into the volume formula:

V=93 V = 9^3

Step 8: Calculate the cube:

V=729 V = 729

Thus, the length of the side of the cube is 9\mathbf{9} and the volume of the cube is 729\mathbf{729}.

The final answer matches the given multiple choice result:

a=9,V=729 a=9,V=729

Answer

a=9,V=729 a=9,V=729

Exercise #2

The length of each edge in the cube is 8 cm.

Calculate the volume and area of the cube.

888

Video Solution

Step-by-Step Solution

To solve this problem, we will calculate the volume and surface area of a cube with edge length 8 cm.

  • Step 1: Calculate the volume of the cube using the formula V=a3 V = a^3 .

Given that the edge length a=8 a = 8 cm, the volume is calculated as follows:

V=83=8×8×8=512 cm3 V = 8^3 = 8 \times 8 \times 8 = 512 \text{ cm}^3

  • Step 2: Calculate the surface area of the cube using the formula S=6a2 S = 6a^2 .

Using the same edge length a=8 a = 8 cm, we find the surface area:

S=6×82=6×(8×8)=6×64=384 cm2 S = 6 \times 8^2 = 6 \times (8 \times 8) = 6 \times 64 = 384 \text{ cm}^2

Thus, the calculated volume and surface area of the cube are, respectively, 512 cm3^3 and 384 cm2^2.

Therefore, the correct solution to the problem, matching the given answer choices, is choice 1: V=512,S=384 V = 512, S = 384 .

Answer

V=512,S=384 V=512,S=384

Exercise #3

A cube has edges measuring 5 cm long.

Calculate the volume of the cube.

555

Video Solution

Step-by-Step Solution

To solve this problem, we'll calculate the volume of the cube using the formula for the volume of a cube, which is V=a3 V = a^3 , where a a is the length of an edge.

Step-by-step solution:

  • Step 1: Identify the given length of the cube's edge. Here, a=5 a = 5 cm.
  • Step 2: Apply the formula for the volume of a cube: V=a3 V = a^3 .
  • Step 3: Substitute the value of a a into the formula: V=53 V = 5^3 .
  • Step 4: Calculate 53 5^3 . Since 5×5=25 5 \times 5 = 25 and 25×5=125 25 \times 5 = 125 , we get 53=125 5^3 = 125 .

Therefore, the volume of the cube is 125 125 cm3^3.

Looking at the answer choices, the correct answer is choice 2: 125 125 cm3^3.

Answer

125 125 cm³

Exercise #4

A cube has edges measuring 4 cm long.

What is the volume of the cube?

444

Video Solution

Step-by-Step Solution

The volume of a cube is determined by the formula V=s3 V = s^3 , where s s is the length of each edge of the cube.

Given that each edge of the cube measures 4 4 cm, we proceed as follows:

  • Step 1: Identify the edge length as s=4 s = 4 cm.
  • Step 2: Apply the formula V=s3 V = s^3 .
  • Step 3: Calculate V=43=4×4×4 V = 4^3 = 4 \times 4 \times 4 .

Continuing with the calculation:

  • 4×4=16 4 \times 4 = 16
  • 16×4=64 16 \times 4 = 64

The volume of the cube is therefore 64 64 cubic centimeters.

Therefore, the solution to the problem is  64\ 64 cm³.

Answer

64 64 cm³

Exercise #5

A cube has edges measuring 3 cm.

Calculate the volume of the cube.

333

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the given information.
  • Step 2: Apply the appropriate formula for volume.
  • Step 3: Perform the necessary calculations.

Now, let's work through each step:
Step 1: The problem states that each edge of the cube is 3 cm long.
Step 2: We use the formula for the volume of a cube: V=s3 V = s^3 , where s s is the side length.
Step 3: Substituting the side length into the formula gives us V=33 V = 3^3 . Calculating this, we have:

33=3×3×3=27 3^3 = 3 \times 3 \times 3 = 27 .

Therefore, the volume of the cube is 27 27 cm³.

Given the answer choices, the correct choice is 27 cm³ \textbf{27 cm³} .

Answer

27 27 cm³

Exercise #6

A cube has edges measuring 2 cm.

Calculate the volume of the cube.

222

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the given information - The edge length of the cube is 2 cm.
  • Step 2: Apply the appropriate formula to find the volume of the cube.
  • Step 3: Perform the calculation with the given edge length.

Now, let's work through each step:
Step 1: The problem provides that each edge of the cube measures 2 cm.
Step 2: The formula for the volume of a cube is V=s3 V = s^3 , where s s is the edge length.
Step 3: Plugging in the values, we calculate the volume as follows:

V=23=2×2×2=8 cm3 V = 2^3 = 2 \times 2 \times 2 = 8 \text{ cm}^3

Therefore, the volume of the cube is 8cm3\mathbf{8 \, \text{cm}^3}.

Answer

8 8 cm³

Exercise #7

The cube has edges measuring 1 cm long.

Calculate the volume of the cube.

111

Video Solution

Step-by-Step Solution

To solve this problem, we will follow a straightforward method.

Step 1: Identify the given information.
The problem states that the edge of the cube is 1 cm long.

Step 2: Apply the formula for the volume of a cube.
The volume V V of a cube with edge length a a is given by the formula: V=a3 V = a^3

Step 3: Substitute the given edge length into the formula.
Substituting a=1 a = 1 cm into the formula gives: V=13 V = 1^3

Step 4: Perform the calculation.
Calculate 13 1^3 , which equals 1.

Therefore, the volume of the cube is 1 1 cm³.

Answer

1 1 cm³

Exercise #8

A cube has edges measuring 6 cm.

Calculate the volume of the cube.

666

Video Solution

Step-by-Step Solution

To solve this problem, we will follow these steps:

  • Step 1: Identify the given information.

  • Step 2: Apply the formula for the volume of a cube.

  • Step 3: Perform the calculation to find the volume.

Let's work through these steps:

Step 1: The problem states a cube with edge length a=6 a = 6 cm.

Step 2: The formula to calculate the volume of a cube is V=a3 V = a^3 .

Step 3: Substitute the given edge length:

V=63 V = 6^3

V=6×6×6 V = 6 \times 6 \times 6

V=216 V = 216 cm3

Therefore, the volume of the cube is 216 216 cm³.

Answer

216 216 cm³

Exercise #9

The edges of a cube are 7 cm long.

Calculate the volume of the cube.

777

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the given information
  • Step 2: Apply the appropriate formula
  • Step 3: Perform the necessary calculations

Now, let's work through each step:

Step 1: Identify the given information.
The length of each edge of the cube is given as 7 7 cm.

Step 2: Apply the appropriate formula.
The formula for the volume V V of a cube where each edge is of length s s is given by V=s3 V = s^3 .

Step 3: Perform the necessary calculations.
Plugging in the value of s=7 s = 7 cm, we compute the volume as follows:
V=73=7×7×7=343 cm3 V = 7^3 = 7 \times 7 \times 7 = 343 \text{ cm}^3

Therefore, the volume of the cube is 343 343 cm³.

Answer

343 343 cm³

Exercise #10

The edges of a cube measure 8 cm.

Calculate the volume of the cube.

888

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the given information
  • Step 2: Apply the formula for the volume of a cube
  • Step 3: Perform the necessary calculations to find the volume

Now, let's work through each step:
Step 1: The problem gives us the edge length of the cube as 8 cm.
Step 2: We'll use the formula for the volume of a cube, which is V=s3 V = s^3 , where s s is the edge length.
Step 3: Plugging the edge length into the formula, we have V=83 V = 8^3 . This calculates to:
V=8×8×8=512 V = 8 \times 8 \times 8 = 512 .

Therefore, the volume of the cube is 512 512 cm³, which is option 2 from the choices given.

Answer

512 512 cm³

Exercise #11

The edges of a cube are 0.5 cm long.

Calculate the volume of the cube.

0.50.50.5

Video Solution

Step-by-Step Solution

To solve this problem, we will calculate the volume of a cube using the standard formula for its volume:

  • Volume formula of a cube: V=s3 V = s^3 , where s s is the side length.

Given that each edge of the cube is 0.5 cm, we substitute this value into the formula:

V=(0.5cm)3 V = (0.5 \, \text{cm})^3

Calculating the cube of 0.5:

0.53=0.5×0.5×0.5 0.5^3 = 0.5 \times 0.5 \times 0.5

=0.25×0.5 = 0.25 \times 0.5

=0.125cm3 = 0.125 \, \text{cm}^3

However, it is important to recognize that the calculations when simplified produce a fraction:

0.125 0.125 can be written in fraction form as 18 \frac{1}{8} .

Therefore, the volume of the cube is 18cm3 \frac{1}{8} \, \text{cm}^3 , which matches the given answer choice.

Answer

18 \frac{1}{8} cm³

Exercise #12

A cube has edges measuring 10 cm long.

Calculate the volume of the cube.

101010

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the given information.
  • Step 2: Apply the appropriate formula for calculating the volume of a cube.
  • Step 3: Perform the necessary calculation to find the volume.

Let's work through each step:
Step 1: We know the length of each edge of the cube is 10 cm.
Step 2: The formula for the volume V V of a cube with side length s s is given by V=s3 V = s^3 .
Step 3: Plugging the given side length into the formula, we get:
V=103=1000 V = 10^3 = 1000 cm³.

Therefore, the volume of the cube is 1000 1000 cm³.

Answer

1000 1000 cm³

Exercise #13

What is the volume of a cube with sides measuring 2X?

2X2X2X

Video Solution

Step-by-Step Solution

To find the volume of a cube, we use the formula:

V=side3 V = \text{side}^3

Here, the side length of the cube is given as 2X2X. Substituting this into the formula gives:

V=(2X)3 V = (2X)^3

To expand this expression, apply the cube to every part of the expression:

V=23×X3 V = 2^3 \times X^3

V=8×X3 V = 8 \times X^3

Thus, the volume of the cube is:

V=8X3 V = 8X^3

Therefore, the correct answer is:

8X3 8X^3

Thus, the solution to the problem is 8x3 8x^3 .

Answer

8x3 8x^3