The KE of e is 4.55 x 10^ -25J. Calculate its wavelength

Question

The KE of e is 4.55 x 10^ -25J. Calculate its wavelength

Answer 1

KE= 1/2mv^2, or 1/2 x 9.108 x 10^-31 x v^2=4.55x10^-25

or, v = 10^3m/S

Wavelength = h/mv = 6.626x10^-34/9.108x10^-31x10^3

  =0.725x10^- 6m

Answer 2

ENERGY (E)=(h*C)/wavelength

hence

wavelength= h*c/e

=6.64*10^ -34*3*10^8/4.55*10^-25

=4.7648 10^ 9

just check if value of plancks constant is right

i hope h= 6.64*10^-34