A particle of mass '\( m \)' is moving in time '\( t \)' on a trajectory given by
\( \vec r = 10 \alpha t^{2}\,\hat{i} + 5\beta (t-5)\,\hat{j} \)
Where \( \alpha \) and \( \beta \) are dimensional constants.
The angular momentum of the particle becomes the same as it was for \( t = 0 \) at time \( t = \) __________ seconds.
