SOLUTION: A particle moves along a horizontal line. Position function is s(t) for t is greater or equal to 0. Find the intervals of time when the particle is moving left and moving right.

Algebra ->  Number-Line -> SOLUTION: A particle moves along a horizontal line. Position function is s(t) for t is greater or equal to 0. Find the intervals of time when the particle is moving left and moving right.       Log On


   

Question 1101603: A particle moves along a horizontal line. Position function is s(t) for t is greater or equal to 0. Find the intervals of time when the particle is moving left and moving right.
s(t) = t^2 -16t +28
I got v(t) = 2t-16 so t= 8
a(t) = 2 but what is t for a(t)?
and how do you use a number line with that?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
the first derivative is 0 at t=8
Here is the graph.
graph%28300%2C300%2C-5%2C15%2C-50%2C40%2Cx%5E2-16x%2B28%2C2x-16%29
The particle is moving left from [0, 8). and it is moving right from (8, oo). ANSWER
At t=8 the instantaneous velocity is 0.
Can visualize moving left as down in this instance and moving right as up. The x-intercepts are only where the particle is at 0, which is not a consideration here.