Question

Find the acceleration. I don’t understand this, please help

Answer 1

At t = 9, Whitney's acceleration will be -0.2 miles per minute.

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:

`\displaystyle m=(0-0.8)/(11-7)=(-0.8)/(4)=-(1)/(5)`

So, a(t) = v'(t) = -0.2 ∀t ∈ t . Then at t = 9, Whitney's acceleration will be -0.2 miles per minute.