# Question #878c8

$\frac{1}{2} {\left(T + U\right)}_{o} = {U}_{o}$
$\implies {T}_{o} = {U}_{o}$
(This only makes sense if the ball is moving downward at ${t}_{o}$ with velocity ${v}_{o}$.)
$\implies {v}_{o} = \sqrt{2 g h} = \sqrt{2 \cdot g \cdot 10} \approx 14 \text{ m/s}$