Similarly distance travelled by the bus will be \(\frac{1}{2}a{t^2}\) for the given condition
\(ut = 50 + \frac{1}{2}a{t^2} = 50 + \frac{{{t^2}}}{2}\) [\(a = 1\;m/{s^2}\)]
\(⇒\) \( u = \frac{{50}}{t} + \frac{t}{2}\)
To find the minimum value of \(u\)
\(\frac{{du}}{{dt}} = 0\), so we get \(t = 10\sec \), then \(u = 10\;m/s\)
($g = 9.8\,m/{s^2}$)