Denali, which is about 20,000 ft above sea level, is the highest mountain in the United States. Mt. Everest, the highest mountain on Earth, is about $9 \times 10^3\text{ ft}$ higher than Denali. About how high is Mt. Everest? The answer should be in scientific notation.


A$1.1 \times 10^3\text{ ft}$
B$29,000\text{ ft}$
C$2.9 \times 10^3\text{ ft}$
D$2.9 \times 10^4\text{ ft}$

Verified Answer :

  • Convert the given heights to standard numerical form: Denali is \(20,000\) ft and the difference is \(9,000\) ft.
  • Sum these values to find the height of Mt. Everest: \(20,000 + 9,000 = 29,000\) ft.
  • Express the result in scientific notation by moving the decimal point: \(2.9 \times 10^4\) ft.
  • The final answer is \(\boxed{2.9 \times 10^4 \text{ ft.}}\)

Explanation

  1. Analyzing the Problem

We are given that the height of Denali is approximately \(20,000\) ft above sea level. Mt. Everest is known to be \(9 \times 10^3\) ft higher than Denali. We need to calculate the height of Mt. Everest and express it in scientific notation. Scientific notation is a way of writing numbers that are too large or too small to be conveniently written in decimal form, represented as \(a \times 10^n\), where \(1 \le |a| < 10\) and \(n\) is an integer.

  1. Converting Values to Standard Form

First, let's represent the given heights in standard numerical form. The height of Denali is \(20,000\) ft. The additional height of Mt. Everest compared to Denali is \(9 \times 10^3\). Since \(10^3 = 1,000\), we have \(9 \times 1,000 = 9,000\). Therefore, the additional height is \(9,000\) ft.

  1. Calculating the Total Height and Converting to Scientific Notation

To find the total height of Mt. Everest, we add the height of Denali and the additional height:
\[20,000 + 9,000 = 29,000 \text{ ft}.\]
Now, we need to convert \(29,000\) into scientific notation. We move the decimal point four places to the left to place it after the first digit (which is 2), giving us \(2.9\). Since we moved the decimal point four places to the left, we multiply by \(10^4\). Thus, the height of Mt. Everest is \(2.9 \times 10^4\) ft.

Examples

Scientific notation is extremely useful in real-world applications involving very large or small numbers, such as astronomy or particle physics. For example, the distance from Earth to the Sun is about \(1.496 \times 10^8\) km. By using scientific notation, scientists avoid long strings of zeros and can perform calculations more efficiently, reducing the risk of errors in complex scientific research.