/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 5 A tiny sphere has a radius of \(... [FREE SOLUTION] | 91Ó°ÊÓ

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A tiny sphere has a radius of \(0.0000000001=10^{-10}\) meter, which is roughly equivalent to the radius of a protein molecule. Answer the following questions. Express your answers in scientific notation. a. Find its surface area, \(S,\) in square meters, where \(S=4 \pi r^{2}\) b. Find its volume, \(V,\) in cubic meters, where \(V=\frac{4}{3} \pi r^{3}\). c. Find the ratio of the surface area to the volume. d. As \(r\) increases, does the ratio in part (c) increase or decrease?

Short Answer

Expert verified
Surface area = \( 4\pi \times 10^{-20} \) sq. meters; Volume = \(\frac{4}{3}\pi \times 10^{-30} \) cubic meters; Ratio of surface area to volume = \( 3 \times 10^{10} \); Ratio decreases as radius increases.

Step by step solution

01

Calculate Surface Area

Given the radius of the tiny sphere, calculate its surface area using the formula for the surface area of a sphere: \[S = 4 \, \pi \, r^2\]
02

Substitute Radius into Surface Area Formula

Given \( r = 10^{-10} \) meters, substitute this value into the surface area formula: \[S = 4 \, \pi \, (10^{-10})^2\]which simplifies to \[S = 4 \, \pi \, (10^{-20})\]and so the surface area \( S \) is: \[S = 4 \, \pi \, (10^{-20}) \, \text{square meters}\]
03

Calculate Volume

Next, calculate the volume using the formula for the volume of a sphere: \[V = \frac{4}{3} \, \pi \, r^3\]
04

Substitute Radius into Volume Formula

Given \( r = 10^{-10} \) meters, substitute this value into the volume formula: \[V = \frac{4}{3} \, \pi \, (10^{-10})^3\]which simplifies to \[V = \frac{4}{3} \, \pi \, (10^{-30})\]and so the volume \( V \) is: \[V = \frac{4}{3} \, \pi \, (10^{-30}) \, \text{cubic meters}\]
05

Find the Ratio of Surface Area to Volume

Using the surface area \( S \) and volume \( V \) calculated, find the ratio: \[\text{Ratio} = \frac{S}{V} = \frac{4 \, \pi \, (10^{-20})}{ \frac{4}{3} \, \pi \, (10^{-30})} \]Simplify the ratio: \[\text{Ratio} = \frac{4 \, \pi \, (10^{-20}) \times \frac{3}{4 \pi}}{10^{-30}} \]which simplifies to: \[\text{Ratio} = \frac{3 (10^{-20})}{(10^{-30})} = 3 \times 10^{10}\]Therefore, the ratio is \[\text{Ratio} = 3 \times 10^{10}\]
06

Determine Behavior as Radius Increases

Observe how the ratio \( \frac{S}{V} \) changes as \( r \) increases. Note that: \[\text{Ratio} = \frac{S}{V} = \frac{4 \, \pi \, r^2}{ \frac{4}{3} \, \pi \, r^3} = 3/r\] As \( r \) increases, the ratio \( \frac{3}{r} \) decreases.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Surface Area of a Sphere
The surface area of a sphere refers to the total area that covers the outer layer of the sphere. It can be found using the formula: \( S = 4 \, \pi \, r^2 \), where \( S \) stands for the surface area and \( r \) for the radius of the sphere.

In our exercise, with \( r = 10^{-10} \) meters, the surface area is calculated as follows:
  • First, we substitute the radius into the formula: \( S = 4 \, \pi \, (10^{-10})^2 \)
  • This simplifies to: \( S = 4 \, \pi \, (10^{-20}) \)
Therefore, the surface area of the sphere is \( 4 \, \pi \, (10^{-20}) \) square meters. This calculation demonstrates the importance of the radius in determining how much space the surface of a sphere occupies.
Volume of a Sphere
The volume of a sphere determines the amount of space it occupies in three dimensions. The formula to compute the volume is: \( V = \frac{4}{3} \, \pi \, r^3 \), where \( V \) denotes volume and \( r \) the radius.

Using our given radius \( r = 10^{-10} \) meters, we can calculate the volume with the following steps:
  • Substitute the radius into the volume formula: \( V = \frac{4}{3} \, \pi \, (10^{-10})^3 \)
  • This simplifies to: \( V = \frac{4}{3} \, \pi \, (10^{-30}) \)
Hence, the volume of our tiny sphere is \( \frac{4}{3} \, \pi \, (10^{-30}) \) cubic meters. This computation demonstrates how dramatically the volume decreases as the radius reduces, given the radius is raised to the power of three.
Ratios in Mathematics
Ratios provide a way to compare two numbers or quantities, emphasizing the relationship between them. In this exercise, we need to find the ratio of the surface area to the volume of a sphere.

From our previous calculations, we have:
  • Surface area \( S = 4 \, \pi \, (10^{-20}) \)
  • Volume \( V = \frac{4}{3} \, \pi \, (10^{-30}) \)
The ratio is then: \( \text{Ratio} = \frac{S}{V} = \frac{4 \, \pi \, (10^{-20})}{ \frac{4}{3} \, \pi \, (10^{-30})} \)

Simplifying this, we get:
  • Cancel terms: \( \text{Ratio} = \frac{4 \, \pi \, (10^{-20}) \times \frac{3}{4 \, \pi}}{10^{-30}} = \frac{3 (10^{-20})}{(10^{-30})} \)
  • This reduces to: \( 3 \times 10^{10} \)
Thus, the ratio of the surface area to volume is \( 3 \times 10^{10} \). Ratios help to understand the proportional differences between different properties of geometric shapes.
Power of Ten
The 'power of ten' notation, also known as scientific notation, provides a way to express very large or very small numbers compactly. In mathematical terms, it's written as \( 10^n \), where \( n \) indicates the power or exponent.

Here’s how it is useful:
  • \( 10^3 = 1000 \)
  • \( 10^{-3} = 0.001 \)
This notation helps transform complex calculations into simpler forms, ensuring clarity and precision.

For example, in our problem, the radius was given as \( 10^{-10} \) meters. Not only does this make the number more manageable, but it’s also easier to use in formulas.

In our surface area calculation, \( (10^{-10})^2 \) is simplified to \( 10^{-20} \). Similarly, in the volume calculation, \( (10^{-10})^3 \) is simplified to \( 10^{-30} \). Working with powers of ten keeps mathematical operations streamlined, especially when dealing with very tiny or enormous quantities.

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Most popular questions from this chapter

a. (Graphing program recommended.) Make a table of values and sketch a graph for each of the following functions. \(\mathrm{Be}\) sure to include negative and positive values for \(x\), as well as values for \(x\) that lie close to zero. $$ y_{1}=\frac{1}{x} \quad y_{2}=\frac{1}{x^{2}} \quad y_{3}=\frac{1}{x^{3}} \quad y_{4}=\frac{1}{x^{4}} $$ b. Describe the domain and range of each function. c. Describe the behavior of each function as \(x\) approaches positive infinity and as \(x\) approaches negative infinity. d. Describe the behavior of each function when \(x\) is near \(0 .\)

The data in the table satisfy the equation \(y=k x^{n}\), where \(n\) is a positive integer. Find \(k\) and \(n\). $$ \begin{array}{ccccc} \hline x & 2 & 3 & 4 & 5 \\ y & 1 & 2.25 & 4 & 6.25 \\ \hline \end{array} $$

Find the value for \(k\), the constant of proportionality, if: a. \(y=\frac{k}{x}\) and \(y=3\) when \(x=2\). b. \(y=\frac{k}{x^{2}}\) and \(y=\frac{1}{4}\) when \(x=8\). c. \(y=\frac{k}{x^{2}}\) and \(y=\frac{1}{16}\) when \(x=2\). d. \(y=\frac{k}{\sqrt{x}}\) and \(y=1\) when \(x=9\).

Assume \(y\) is inversely proportional to the cube of \(x\). a. If \(x\) doubles, what happens to \(y\) ? b. If \(x\) triples, what happens to \(y\) ? c. If \(x\) is halved, what happens to \(y ?\) d. If \(x\) is reduced to one-third of its value, what happens to \(y\) ?

(Graphing program optional.) Graph the functions \(f(x)=\frac{1}{x^{2}}\), \(g(x)=\frac{4}{x^{2}},\) and \(h(x)=\frac{1}{4 x^{2}}\) For parts \((a)-(c),\) insert the symbol \(>\) or \(<\) to make the relation true. a. For \(x>0, f(x) \longrightarrow g(x)\) b. For \(x>0, g(x) \longrightarrow h(x)\) c. For \(x>0, h(x) \quad f(x)\) d. Describe how the graphs are related to each other when \(x<0 .\) Generalize your findings to any value for the coefficient \(k>0\)

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