Çözüldü Quantum Mechanics - de Broglie Wavelength and Kinetic Energy

If the de Broglie wavelengths of two moving X and Y particles with masses m and 3m, respectively, are equal to one another, what is the ratio of the kinetic energies Ex / Ey?

A) 3
B) 1.5
C) 1
D) 2 / 3
E) 1 / 3

λ: Wavelength
h: Planck Constant
λx = h / (2·m·Ex)^0.5
λy = h / (2·3m·Ey)^0.5
λx = λy ⇒ h / (2·m·Ex)^0.5 = h / (2·3m·Ey)^0.5 ⇒ 2·3m·Ey = 2·m·Ex ⇒ 3 = Ex / Ey.

Source:https://www.ck12.org/flexi/physical...ie-wavelength-calculator-with-kinetic-energy/