Answer:
2.04 miles per hour
Step-by-step explanation:
Given
Noel
[tex]n_1 =6miles[/tex]
[tex]r_1 = 2mph[/tex]
Casey
[tex]c_1 = 8miles[/tex]
[tex]r_2 =1mph[/tex]
Required
The rate at which the distance increases
Their movement forms a right triangle and the distance between them is the hypotenuse.
At [tex]n_1 =6miles[/tex] and [tex]c_1 = 8miles[/tex]
The distance between them is:
[tex]d_1 = \sqrt{n_1^2 + c_1^2}[/tex]
[tex]d_1 = \sqrt{6^2 + 8^2}[/tex]
[tex]d_1 = \sqrt{100}[/tex]
[tex]d_1 = 10miles[/tex]
After 1 hour, their new position is:
New = Old + Rate * Time
[tex]n_2 = n_1 + r_1 * 1[/tex]
[tex]n_2 = 6 + 2 * 1 = 8[/tex]
And:
[tex]c_2 = c_1 + r_2 * 1[/tex]
[tex]c_2 = 8 + 1 * 1 = 9[/tex]
So, the distance between them is now:
[tex]d_2 = \sqrt{n_2^2 + c_2^2}[/tex]
[tex]d_2 = \sqrt{8^2 + 9^2}[/tex]
[tex]d_2 = \sqrt{145}[/tex]
[tex]d_2 = 12.04[/tex]
The rate of change is:
[tex]\triangle d = d_2 -d_1[/tex]
[tex]\triangle d = 12.04 -10[/tex]
[tex]\triangle d = 2.04[/tex]
