For any microscope, the size of the smallest observable object is one-half the wavelength of the radiation used. For example, the smallest object observable with 400 -nm light is $2 \times 10^{-7} \mathrm{~m}$. (a) What is the smallest observable object for an electron microscope using electrons moving at $5.5 \times 10^{4} \mathrm{~m} / \mathrm{s} ?$
(b) At $3.0 \times 10^{7} \mathrm{~m} / \mathrm{s} ?$