Determine the volume of the solid of revolution formed when the curve y = 2 is rotated 360° about the x-axis between the limits x = 0 to x = 3.
- A24π
- B8π
- C12π
- D6π
Solution & Step-by-step Explanation
To determine the volume of the solid of revolution formed by rotating a curve about an axis, we commonly use methods like the Disk Method or the Washer Method. In this specific problem, we are given a simple curve,
Volume Calculation using the Disk Method
When a region is rotated about the x-axis, and the solid generated has no hole, the Disk Method is the most suitable approach. The formula for the volume
Let's break down the components given in the problem:
- The function is .
- The axis of revolution is the x-axis.
- The lower limit of integration is .
- The upper limit of integration is .
Applying the Disk Method to the Curve y=2
Now, we will substitute these values into the Disk Method formula to calculate the volume of the solid of revolution.
Step 1: Set up the integral.
Substitute , , and into the volume formula:
Step 2: Simplify the integrand.
Square the function value:
Rearrange the constant:
Step 3: Evaluate the integral.
The integral of is . So, we evaluate from to :
Step 4: Apply the limits of integration.
Substitute the upper limit and subtract the substitution of the lower limit:
Step 5: Calculate the final volume.
The volume of the solid of revolution formed is cubic units. This solid is essentially a cylinder with radius 2 and height 3. The volume of a cylinder is given by . Here, and , so , which confirms our integration result.
y = 2, which is a horizontal line. This line is rotated 360° about the x-axis between the limits x = 0 and x = 3.Volume Calculation using the Disk Method
When a region is rotated about the x-axis, and the solid generated has no hole, the Disk Method is the most suitable approach. The formula for the volume
V using the Disk Method for a function y = f(x) rotated about the x-axis from x = a to x = b is given by:Let's break down the components given in the problem:
- The function is .
- The axis of revolution is the x-axis.
- The lower limit of integration is .
- The upper limit of integration is .
Applying the Disk Method to the Curve y=2
Now, we will substitute these values into the Disk Method formula to calculate the volume of the solid of revolution.
Step 1: Set up the integral.
Substitute , , and into the volume formula:
Step 2: Simplify the integrand.
Square the function value:
Rearrange the constant:
Step 3: Evaluate the integral.
The integral of is . So, we evaluate from to :
Step 4: Apply the limits of integration.
Substitute the upper limit and subtract the substitution of the lower limit:
Step 5: Calculate the final volume.
The volume of the solid of revolution formed is cubic units. This solid is essentially a cylinder with radius 2 and height 3. The volume of a cylinder is given by . Here, and , so , which confirms our integration result.