Answer
$$37$$
Work Step by Step
We start with
$$k=\frac{1}{2}mv^2$$
First, we multiply both sides by $2$ as follows:
$$2k=2\frac{mv^2}{2}\Longrightarrow 2k=mv^2 $$
By dividing by $v^2$, we have
$$\frac{2k}{v^2}= \frac{v^2m}{v^2} \Longrightarrow m= \frac{2k}{v^2} .$$
Now, by substitution, we have $$m= \frac{2k}{v^2} =\frac{2*460 }{5^2}=36.8\approx 37$$
