Which of the following equations represents the velocity $(v)$ of the ejected electrons when a metal is struck with light of frequency $\nu$ and the threshold frequency of the metal is $\nu_0$? ($m_e =$ mass of electron and $h$ is Planck's constant).

• A
  $v = \sqrt{\frac{h(\nu-\nu_0)}{m_e}}$
• B
  $v = \sqrt{\frac{2h(\nu-\nu_0)}{m_e}}$
• C
  $v = \sqrt{\frac{h(\nu-\nu_0)}{2m_e}}$
• D
  $v = \sqrt{h(\nu-\nu_0)m_e}$