If we ASSUME it was linear...
The slope is (9000-16800)/2=-3900
V(t)=16800-3900t
V(5)=-2700 haha, so it was not linear...
There are only two data points so we can not create a quadratic equation with any certainty to determine acceleration or d2y/dx2 constant.
We can however "model" it as exponential decay...
9000=16800r^2
15/28=r^2
F(t)=16800(15/28)^(t/2)
F(5)=3528.92 (or 3529.00 to nearest dollar)
