/*! 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 14 The Mississippi River: For purpo... [FREE SOLUTION] | 91Ó°ÊÓ

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The Mississippi River: For purposes of this exercise, we will think of the Mississippi River as a straight line beginning at its headwaters, Lake Itasca, Minnesota, at an elevation of 1475 feet above sea level, and sloping downward to the Gulf of Mexico 2340 miles to the south. a. Think of the southern direction as pointing to the right along the horizontal axis. What is the slope of the line representing the Mississippi River? Be sure to indicate what units you are using. b. Memphis, Tennessee, sits on the Mississippi River 1982 miles south of Lake Itasca. What is the elevation of the river as it passes Memphis? c. How many miles south of Lake Itasca would you find the elevation of the Mississippi to be 200 feet?

Short Answer

Expert verified
a. -0.63 feet/mile; b. 210.14 feet; c. 2021.43 miles.

Step by step solution

01

Understand the Problem

The Mississippi River is modeled as a straight line sloping downward. We need to find the slope (a rate of elevation decrease per mile) and calculate elevations at specific mile markers.
02

Define the Slope

The slope of a line is calculated as \( m = \frac{{\text{change in vertical height}}}{{\text{change in horizontal distance}}} \). Here the change in height is from 1475 feet to 0 feet over 2340 miles. Thus, \( m = \frac{{1475 - 0}}{{0 - 2340}} = \frac{{1475}}{{2340}} \) feet per mile.
03

Calculate the Slope Value

Calculate the slope: \( m = \frac{1475}{2340} \approx -0.63 \). This means the river drops approximately 0.63 feet for every mile towards the south.
04

Calculate Elevation at Memphis

Use the slope to calculate the elevation at Memphis 1982 miles south of Lake Itasca. The elevation at any point can be calculated using \( \, ext{elevation} = 1475 + m \times ext{distance} \, \). Here it's \( \, 1475 + (-0.63) \, \times \,(1982) \, \).
05

Compute Elevation at Memphis

Substitute the known values into the elevation equation: \( \, 1475 - 0.63 \times 1982 = 210.14 \) feet.
06

Identify Miles for Given Elevation

To find where the elevation is 200 feet, use the equation again: \( 200 = 1475 + (-0.63) \times x \, \) where \( x \, \) is the distance south.
07

Solve for Distance when Elevation is 200 feet

Rearrange the equation for \( x \): \( x = \frac{200 - 1475}{-0.63} \approx 2021.43 \, \text{miles} \).

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Key Concepts

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

Slope of a Linear Function
In mathematics, the slope is a measure of the steepness of a line. When you look at the Mississippi River as a straight line on a graph, the slope tells you how quickly this river drops as it moves southward. This is calculated as the change in vertical height divided by the change in horizontal distance. In this case, the river starts at 1,475 feet above sea level at Lake Itasca and descends to sea level over 2,340 miles. The formula used to calculate the slope is as follows:\[ m = \frac{\text{change in height}}{\text{distance}} = \frac{1475 - 0}{0 - 2340} = \frac{1475}{2340} \]This results in a slope of approximately \(-0.63\) feet per mile, which indicates that for every mile you move south, the river drops about 0.63 feet. A negative slope indicates the river goes downward, making it easier to picture the steady descent from Minnesota to the Gulf of Mexico.
Elevation Calculation Along the River
Elevation calculations are crucial for understanding a river's path and impact over geography. We use the slope in situations where we want to find out how high or low a location is compared to the starting point.In the case of Memphis, Tennessee, which is 1,982 miles from the starting point, we can calculate the elevation like this:1. Start with the elevation at Lake Itasca (1,475 feet).2. Apply the slope for the distance to Memphis.The equation is:\[\text{Elevation at Memphis} = 1475 + (-0.63) \times 1982\]Substituting the values gives us:\[= 1475 - 1248.66 \approx 210.14 \text{ feet}\]This means that as the Mississippi River passes Memphis, it is about 210 feet above sea level.
Mathematical Modeling of River Elevation
Mathematical modeling helps us predict elevations along a river without needing to measure each point. By understanding the slope, we can create an equation. This equation models the river's elevation, allowing us to calculate heights at various points.Given the equation:\[\text{elevation} = 1475 + (-0.63) \times x\]Where \(x\) is the distance in miles from Lake Itasca, we can adjust this equation to find the elevation at any kilometer point. For example, finding a specific elevation like 200 feet:1. Set up the equation: \(200 = 1475 + (-0.63) \times x\)2. Solve for \(x\): \[x = \frac{200 - 1475}{-0.63} \approx 2021.43 \text{ miles}\]This mathematical model ensures we can determine distance, like 2021 miles, where the river falls to 200 feet. This is helpful in planning and assessment of geographical features.
Understanding River Geography
Rivers are vital geographical features, and understanding their slope and elevation fundamentally changes how we look at terrain and waterways. **Key Facts about River Geography:** - Rivers typically flow from areas of high elevation to low. - The Mississippi River, with its starting point at Lake Itasca, is a clear example of a river traversing major geographical expanses. - As a river progresses, it shapes the land, creating significant geographical features like valleys and floodplains. In the context of the Mississippi, its gentle slope causes gradual changes in elevation, providing a steady pathway to the Gulf of Mexico. From a geographical standpoint, understanding these features is crucial for navigation, construction, and environmental conservation. Knowing the river's slope and elevation also informs us of potential flooding areas and sediment deposits, impacting both human activities and wildlife habitats.

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