How can one calculate the velocity of an electron using de Broglie equation, if only the wavelength is given?

Answer 1

if you're given the wavelength "L" can't you use the equation
L = h/(mv)?

Answer 2

wavelength=h/p=h/(mv)

you know wavelength and h
if this is a homework problem, then I would suggest checking the back of the book for the fundamental charts. usually physics books will have the mass of the electron. if not, then yahoo it or google it