Answer: The answer is 314.28 cm² (approx.).
Step-by-step explanation: Given that an engineer is going to install a new water pipe. The diameter of this circular pipe is, d = 20 cm.
We need to find the area 'A' of the circular cross-section of the pipe.
Given, diameter of the circular section is
So, the radius of the circular cross-section will be
Therefore, cross-sectional area of the pipe is
Thus, the answer is 314.28 cm² (approx.).
Using the given information and what we know about linear equations, we will find the sketch below.
<h3>How to sketch a graph?</h3>Here we need to analyze each part separately.
In a coordinate axis where the y-axis represents distance and the x-axis represents time, we will have that:
First, we know that he rides for 30 minutes at a given speed, this will be represented with an increasing linear function.
Then he stops for 20 minutes, this is represented with a horizontal line.
Finally, he returns the motion, but slower than before, so the slope of this line will be smaller than the first one.
So for 0 to 30 we have an increasing linear equation, then for 30 to 50 we have a constant horizontal line, then for 50 to 80 we have another increasing linear equation
The sketch can be seen below.
If you want to learn more about linear equations, you can read:
