Physics

Problem

Two electrons are moving with non-relativistic speeds perpendicular to each other. If corresponding de Broglie wavelengths are

\lambda_1

and

\lambda_2

, their de Broglie wavelength in the frame of reference attached to their centre of mass is: [Main Online April 15, 2018] (a)

\lambda_{CM} = \lambda_1 = \lambda_2

(b)

\frac{1}{\lambda_1} = \frac{1}{\lambda_1} + \frac{1}{\lambda_2}

(c)

\lambda_{CM} = \frac{2\lambda_1\lambda_2}{\sqrt{\lambda_1^2 + \lambda_2^2}}

(d)

\lambda_{CM} = \left(\frac{\lambda_1 + \lambda_2}{2}\right)