Part A

In a ballistic pendulum experiment, projectile $1$ results in a maximum height $h$ of the pendulum equal to $2\mathrm{.}3$ cm $.$A second projectile $($of the same mass$)$ causes the The second projectile was how many times faster than the first? pendulum to swing twice as high, $h_2=4\mathrm{.}6cm.$

Express your answer numerically.