Seemingly easy quantum question

1. Mar 25, 2005

bemigh

Hey, i dont understand why i cant seem to find this answer??
Im given the length of the box, the mass, the value of n, i can solve for E of the particle, then using E=hf, solve for eventually the wavelength.
Is their something wrong with my process??

A particle of mass 2.13×10-28 kg is confined to a one-dimensional box of width 1.18×10-10 m. For n = 1 , what is the particle's wavelength?

Cheers

2. Mar 26, 2005

Gamma

I would use the relation $$E^2 = p^2c^2 + m_0 c^2$$ (relativistic energy) to find E and then use the De broglie relation to find lamda. E = hf wouldn't work since we are dealing with a particle with mass.