Answer
11.05
Note, since air resistance was considered, the maximum height is lower, causing the value of g to appear higher than it actually is.
Work Step by Step
We know from conservation of energy that $v=\sqrt{2gh}$, and we know that $v=\frac{J}{m}$. (Note, m is mass, g is the gravitational constant, h is the height, and J is the impulse). Setting these equal, we find:
$2gh = \frac{J^2}{m^2}$
Thus, we could plot $J^2$ versus $2hm^2$. We could also plot $\frac{J^2}{m^2}$ versus 2h. Doing this, we find the experimental gravitational constant to be:
11.05.
Note, since air resistance was considered, the maximum height is lower, causing the value of g to appear higher than it actually is.