Answer
At the point $0.82m$ from the rotation axis, we have $a_T=g=9.8m/s^2$
Work Step by Step
We have the blade's angular acceleration $\alpha=+12rad/s^2$
The blade's tangential acceleration can be calculated by $$a_T=r\alpha$$
For $a_T=g=9.8m/s^2$, $r$ needs to be $$r=\frac{9.8}{12}=0.82m$$
