what should be the velocity of an electron so that its momentum becomes equal to that of a photon of wavelength `5200 Å`

Options

A. `700m//s`
B. `1000m//s`
C. `1400m//s`
D. `2800m//s`

Answer

C

Explanation

Momentum `rho=mv=h/(lamda)`
`implies v=h/(m lamda)`
`:.v=(6362xx10^(-34))/(9.1xx10^(-31)xx5.2xx10^(-7))`
`implies v=(6.62xx10^(4))/(9.1xx5.2)`
`impliesv=1.4xx10^(3)m//s`
`impliesv=1400m//s`