Chapter 4: Problem 83
\(d V\) if a circular cylinder of height 3 changes from \(r=2\) to \(r=1.9 \mathrm{cm} .\)
Short Answer
Expert verified
The change in volume is approximately \(1.17\pi\) cm³.
Step by step solution
01
Understand the Volume Formula
The volume of a cylinder is given by the formula: \( V = \pi r^2 h \). Here, \( r \) is the radius, \( h \) is the height, and \( \pi \) is a constant (approximately 3.14159). For this problem, the height \( h = 3 \) cm.
02
Calculate the Initial Volume
Calculate the initial volume with radius \( r = 2 \) cm using the formula: \( V_1 = \pi (2)^2 \times 3 = 12\pi \) cm³.
03
Calculate the Final Volume
Calculate the final volume with radius \( r = 1.9 \) cm using the formula: \( V_2 = \pi (1.9)^2 \times 3 = 10.83\pi \) cm³.
04
Find the Change in Volume
Subtract the final volume from the initial volume to find the change in volume: \( \Delta V = V_1 - V_2 = 12\pi - 10.83\pi = 1.17\pi \) cm³.
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Volume Formula
To understand the volume of a cylinder, it's important to grasp the volume formula: \[ V = \pi r^2 h \]This formula calculates the space within a cylinder. Here, \( V \) denotes the volume, \( r \) is the radius of the circular base, \( h \) is the height of the cylinder, and \( \pi \) is a mathematical constant (approximately 3.14159). It is used since the base of the cylinder is a circle.
Using this formula helps us determine the volume before and after any changes in the cylinder’s dimensions.
- The term \( \pi r^2 \) represents the area of the circular base.
- Multiplying by the height \( h \) gives the 3-dimensional space volume.
Using this formula helps us determine the volume before and after any changes in the cylinder’s dimensions.
Radius Change
A change in the radius of a cylinder significantly impacts its volume. In our problem, the radius changes slightly from \( r = 2 \) cm to \( r = 1.9 \) cm. This change might seem minor, but it affects the entire volume of the cylinder.
Remember that the radius is squared in the volume formula:
Remember that the radius is squared in the volume formula:
- This means even a small change in the radius leads to a larger difference when squared.
- The smaller radius square will produce a smaller base area for the volume calculation.
Cylinder Height
The height of the cylinder, marked as \( h \) in the volume formula, is straightforward in this exercise. It is given as 3 cm, which remains constant between the calculations for both radii.
Here’s why height is important:
Here’s why height is important:
- The height extends the circular base into the third dimension, making it a cylinder.
- Any changes in height would proportionally influence the overall volume.
Volume Calculation
The calculation of a cylinder's volume involves using the volume formula twice—once for each radius—to determine the initial and final volumes.
Here’s the step-by-step breakdown:
This simple operation helps demonstrate the effect of changes in the radius on the cylinder's volume.
Here’s the step-by-step breakdown:
- Calculate the initial volume using the radius of 2 cm: \[ V_1 = \pi \times 2^2 \times 3 = 12\pi \text{ cm}^3 \]
- Calculate the final volume with the adjusted radius 1.9 cm: \[ V_2 = \pi \times 1.9^2 \times 3 = 10.83\pi \text{ cm}^3 \]
This simple operation helps demonstrate the effect of changes in the radius on the cylinder's volume.