21. John threw a rock into a lake from a bridge 124 feet above the river's surface. The rock sinks 81 feet below the river’s surface. What is the distance between the elevations? (Hint: Draw a picture or use a number line.)(1 point)
Responses
-205 feet
-205 feet
205 feet
205 feet
43 feet
43 feet
-43 feet
-43 feet
The distance between the elevations can be found by subtracting the depth the rock sank from the height of the bridge:
124 feet - 81 feet = 43 feet
Therefore, the distance between the elevations is 43 feet. The correct answer is 43 feet.
To find the distance between the elevations, we need to calculate the difference between the bridge height and the depth at which the rock sinks. Here's how you can solve this problem:
1. Draw a number line or a diagram to visualize the situation. On the number line, mark the bridge height of 124 feet and the depth at which the rock sinks, 81 feet below the river's surface.
2. To find the difference between the two elevations, subtract the depth at which the rock sinks from the bridge height: 124 feet - 81 feet = 43 feet.
Therefore, the distance between the elevations is 43 feet. So, the correct answer is:
43 feet
To find the distance between the elevations, we need to subtract the distance the rock sinks below the river's surface from the height of the bridge.
First, let's calculate the total height from the river's surface to the bridge:
Height of bridge above the river's surface = 124 feet
Next, we need to subtract the distance the rock sinks below the river's surface from the total height:
Distance between elevations = Height of bridge above the river's surface - Distance the rock sinks below the river's surface
Distance between elevations = 124 feet - 81 feet
Distance between elevations = 43 feet
So, the correct answer is 43 feet.