157- Train A, with length 200 m, is moving at constant speed $4\,\dfrac{\text{m}}{\text{s}}$. Train B, with length 225 m, has stopped on the adjacent track. At the moment train A completely passes train B, train B starts moving in the same direction as train A with constant acceleration $2\,\dfrac{\text{m}}{\text{s}^2}$ and brings its speed up to $50\,\dfrac{\text{m}}{\text{s}}$ and continues at that speed. How many seconds after the start of motion does train B completely pass train A? (1) $57.5$ (2) $82.5$ (3) $80$ (4) $105$
\textbf{157-} Train A, with length 200 m, is moving at constant speed $4\,\dfrac{\text{m}}{\text{s}}$. Train B, with length 225 m, has stopped on the adjacent track. At the moment train A completely passes train B, train B starts moving in the same direction as train A with constant acceleration $2\,\dfrac{\text{m}}{\text{s}^2}$ and brings its speed up to $50\,\dfrac{\text{m}}{\text{s}}$ and continues at that speed. How many seconds after the start of motion does train B completely pass train A?
\medskip
(1) $57.5$ \hfill (2) $82.5$ \hfill (3) $80$ \hfill (4) $105$
\medskip