Chapter 11: Problem 75
Use a calculator to solve each equation. Round answers to four decimal places. $$3=10^{x}$$
Short Answer
Step by step solution
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
/*! 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}
Learning Materials
Features
Discover
Chapter 11: Problem 75
Use a calculator to solve each equation. Round answers to four decimal places. $$3=10^{x}$$
These are the key concepts you need to understand to accurately answer the question.
All the tools & learning materials you need for study success - in one app.
Get started for free
In chemistry the \(p H\) of a solution is defined by $$\mathrm{pH}=-\log _{10}[H+]$$ where \(H+\) is the hydrogen ion concentration of the solution in moles per liter. Distilled water has a pH of approximately \(7 . A\) solution with a pH under 7 is called an acid, and one with a pH over 7 is called a base. Roanoke River pH. The hydrogen ion concentration of a water sample from the Roanoke River at Janesville, North Carolina, was \(1.995 \times 10^{-7} \mathrm{mol} / \mathrm{L}\) (wwwnc.usgs.gov). What was the pH of this water sample?
Depreciating knowledge. The value of a certain textbook seems to decrease according to the formula \(V=45 \cdot 2^{-0.9 t}\) where \(V\) is the value in dollars and \(l\) is the age of the book in years. What is the book worth when it is new? What is it worth when it is 2 years old?
For each equation, find the exact solution and an approximate solution when appropriate. Round approximate answers to three decimal places. See the Strategy for Solving Exponential and Logarithmic $$3^{x}=20$$
Solve each problem. The number of grams of a radioactive substance that is present in an old piece of cloth after t years is given by $$A=10 e^{-0.0001 t}$$ How many grams of the radioactive substance did the cloth contain when it was made at time \(t=0 ?\) If the cloth now contains only 4 grams of the substance then when was the cloth made?
For each equation, find the exact solution and an approximate solution when appropriate. Round approximate answers to three decimal places. See the Strategy for Solving Exponential and Logarithmic $$x \cdot \log (3)=\log (5)$$
What do you think about this solution?
We value your feedback to improve our textbook solutions.