λ = h
mv
λ = 6.63x10^-34 m^2 kg/s
(1.67x10^-27kg)(600 m/s)
Wavelength is in meters. You want to cancel the Kg terms, seconds, and one of the m terms. After the multiplication and division, you should get the wavelength. I got 6.616 * 10^-10 m.
