A particle has a de Broglie wavelength of 3.30 10-10 m. Then its kinetic energy quadruples. What is the particle's new de Broglie wavelength, assuming that relativistic effects can be ignored?

Answer 1

λ =h/p,
KE = p^2/2•m
p =sqrt(2•m•KE)
λ1 =h/sqrt(2•m•KE1),
λ2 =h/sqrt(2•m•KE2)=
= h/sqrt(2•m•4•KE1)=
= h/sqrt(4•p)= λ1/2 =
=1.65•10^-10 m.