197- The work functions of metals A and B are $4\text{eV}$ and $2\text{eV}$ respectively, and light with a wavelength of $200$ nanometers shines on both metals. The fastest photoelectrons separated from metal B compared to the fastest photoelectrons separated from metal A are how many times faster? $\left(c = 3\times10^{8}\ \dfrac{\text{m}}{\text{s}}\ \text{ and }\ h = 4\times10^{-15}\ \text{eV.s}\right)$ \[
\frac{1}{2} \quad (4) \qquad\qquad \frac{\sqrt{r}}{r} \quad (3) \qquad\qquad \sqrt{r} \quad (2) \qquad\qquad r \quad (1)
\]
\textbf{197-} The work functions of metals A and B are $4\text{eV}$ and $2\text{eV}$ respectively, and light with a wavelength of $200$ nanometers shines on both metals. The fastest photoelectrons separated from metal B compared to the fastest photoelectrons separated from metal A are how many times faster? $\left(c = 3\times10^{8}\ \dfrac{\text{m}}{\text{s}}\ \text{ and }\ h = 4\times10^{-15}\ \text{eV.s}\right)$
\[
\frac{1}{2} \quad (4) \qquad\qquad \frac{\sqrt{r}}{r} \quad (3) \qquad\qquad \sqrt{r} \quad (2) \qquad\qquad r \quad (1)
\]