In some scattering experiments, the speed of the particles is tuned so that their de Broglie wavelength has a specific value. If a wavelength of $0\mathrm{.}117$ nm is required.

 a$)$ How fast must a neutron be travelling to achieve this wavelength?

 b$)$ How fast would an electron have to travel to possess the same de Broglie wavelength? Is this speed possible?