Question

Calculate the kinetic energy (in J) of a neutron with wavelength 85.3 pm.

Answer 1

E = hc/wavelength. h is Planck's constant of 6.64E-34 Js, c is speed of light = 3E8 m/s, wavelength is given. Convert wavelength to m. 85.3 pm = 85.3E-12 m. Post your work if you get stuck.

Answer 2

I got E = 2.33E-14 J, but that doesn't seem to be the right answer. I'm not really sure where to go from here, do I use Ekinetic = 1/2*mv^2? I'm not sure what the value for speed would be though.