# Question #ebb84

Assuming no resistance, and for launch veclocity ${\vec{v}}_{o}$ at angle $\theta$ to horizontal, it's horizontal velocity throughout is $\left\mid {\vec{v}}_{o} \right\mid \cos \theta \setminus {\vec{e}}_{x}$.
$\left\mid {\vec{v}}_{o} \right\mid = 5 \left\mid {\vec{v}}_{o} \right\mid \cos \theta$
$\implies \theta = {\cos}^{- 1} \setminus \frac{1}{5}$