Step 1: de Broglie Wavelength Formula
The de Broglie wavelength is given by:
\[
\lambda = \frac{h}{\sqrt{2mE}}
\]
Rearranging for kinetic energy \( E \):
\[
E = \frac{h^2}{2m\lambda^2}
\]
Step 2: Computing Ratio
\[
\frac{E_X}{E_Y} = \frac{m_Y \lambda_Y^2}{m_X \lambda_X^2}
\]
Given:
- \( m_X = 9 m_Y \),
- \( \lambda_X = 1 \) nm, \( \lambda_Y = 3 \) nm.
Substituting:
\[
\frac{E_X}{E_Y} = \frac{m_Y (3)^2}{9m_Y (1)^2}
\]
\[
= \frac{9}{9} = 1
\]
Conclusion
Thus, the correct answer is:
\[
9 : 1
\]