## rubyred2012 3 years ago Estimate the wavelength (in nm) of such a proton moving at 2.81x10^8 m/s (mass of a proton = 1.673x10^-27 kg).

$E = \frac{1}{2}m v^2$ where m is the mass and v is the velocity $E = \frac{hv}{\lambda}$ $where \lambda$ is the wavelength. You can equate the two expressions for E, cancel the v and express the wavelength interms of h, m and v