8. When light with a wavelength of 223 nm is incident on a certain metal surface, electrons are ejected with a maximum kinetic energy of 3.32 × 10-19 J. Determine the wavelength of light that should be used to quadruple the maximum kinetic energy of the electrons ejected from this surface.
___________nm
9. A particle has a de Broglie wavelength of 3.00 × 10-10 m. Then its kinetic energy doubles. What is the particle's new de Broglie wavelength, assuming that relativistic effects can be ignored?
___________________m
10. An electron, starting from rest, accelerates through a potential difference of 413 V. What is the final de Broglie wavelength of the electron, assuming that its final speed is much less than the speed of light?
_________________m