Answer
a) $4.17\hat{j}\ m/s$
b) $6.94 \ m/s^2$
Work Step by Step
In order to create the graph, graph all of the x-coordinates along with the corresponding y-coordinates that occur at the same point in time. This will create a sideways parabola, which starts at (0,0) and ends at (0,5).
a) The key idea here is that the question asks for velocity, not speed. Thus, we find:
$\vec{v}=\frac{5-0}{1.2}\hat{j}=4.17\hat{j}\ m/s$
b) The acceleration is centripetal, so we find:
$a =\frac{v^2}{r}=\frac{4.17^2}{2.5}=6.94 \ m/s^2$
