Posted by Matthew on .
i.imgur. com/cqwun. png
i'm kind of stuck.. are the answers 6, 3, 3, and 0?

Physics 
Steve,
6 is the correct 1st answer.
looking at the graph,
a(t) = 3  3/2 (t2) for t>=2
so,
v(t) = 6t  3/4 t^2
v(2) = 6*2  3/4 * 4 = 9
v(4) = 6*4  3/4 * 16 = 12
so, ∆v = 3
Note that even though a is decreasing, it is still positive, so v will be increasing
v(6) = 6*6  3/4 * 36 = 9
so, ∆v = 3
from t=0 to 6, v went +6 +3 3 = +6