Question

what should be the velocity of an electron so that its momentum becomes equal to that of a photon of wavelength `5200 Å`
A. 700m/s
B. 1000 m/s
C. 1400 m/s
D. 2800 m/s

Answer 1

Correct Answer - C
`P_(e)=O_(ph)`
`mv=(hc)/(lambda)`
`" " v=(hc)/(lambdaxxm)`
`" " =(6.67xx10^(-34)xx3xx10^(8))/(5200xx10^(-10)xx9.1xx10^(-31))`
`~~ 1400 m//s`