A particle moves on a coordinate line with acceleration StartFraction d squared s Over dt squared EndFraction equals 60 StartRoot t EndRoot minus StartFraction 21 Over StartRoot t EndRoot EndFraction , subject to the conditions that StartFraction ds Over dt EndFraction equals 9 and sequals20 when t equals 1. Find the velocity v equals StartFraction ds Over dt EndFraction in terms of t and the position s in terms of t.