Answer:
At t = 9, Whitney's acceleration will be -0.2 miles per minute.
Step-by-step explanation:
Remember that the acceleration is the derivative of velocity.
Since we want to find Whitney's acceleration at t = 9 and we are given the velocity function, we can simply find the derivative of the point at t = 9. In other words, a(9) = v'(9).
For the interval (7, 11), we simply have a line. So Whitney's acceleration at t = 9 will be equivalent to the slope of that line.
We have the two points (7, 0.8) and (11, 0). So, the slope between them is:
[tex]\displaystyle m=\frac{0-0.8}{11-7}=\frac{-0.8}{4}=-\frac{1}{5}[/tex]
So, a(t) = v'(t) = -0.2 ∀t ∈ {t | 7 < t < 11}. Then at t = 9, Whitney's acceleration will be -0.2 miles per minute.
