\textbf{156.} A particle starts from rest at the origin on the $x$-axis with constant acceleration, and at moment $t = 5\text{s}$ reaches position $x = -122.5\,\text{m}$. How many meters per second does the speed of the particle reach at this moment?
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(1) $19.6$ \hfill (2) $33.4$ \hfill (3) $45.0$ \hfill (4) $49.0$
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