Part I: Estimate the Number of Hours in One Year
To estimate the number of hours in one year using scientific notation, we know there are 24 hours in a day and approximately 365 days in a year. Therefore, we can calculate:
\[ \text{Estimated hours in one year} = 24 , \text{hours/day} \times 365 , \text{days/year} \approx 8,760 , \text{hours/year} \]
In scientific notation, this can be expressed as:
\[ 8,760 \approx 8.76 \times 10^3 , \text{hours} \]
Part II: Calculate the Exact Number of Hours in One Year
To calculate the exact number of hours in one year, we will use the exact value of seconds provided (1 year = 31,556,952 seconds) and the conversion of seconds to hours (1 hour = 3,600 seconds):
\[ \text{Exact hours in one year} = \frac{31,556,952 , \text{seconds/year}}{3,600 , \text{seconds/hour}} \approx 8,760.82 , \text{hours/year} \]
In scientific notation, this can be expressed as:
\[ 8,760.82 \approx 8.76 \times 10^3 , \text{hours} \]
Part III: Comparison of Answers
The results from parts I and II are quite similar; both estimates yield a value of approximately \( 8.76 \times 10^3 \) hours per year. However, part I provides a rough estimate, rounding to \( 8,760 \) hours, while part II offers a more precise calculation, yielding \( 8,760.82 \) hours. This slight difference highlights that while the estimation is close and useful for quick calculations, the exact calculation accounts for the additional fraction of an hour, which can be significant in contexts requiring accuracy.