Question

What speed must an electron have if its momentum is to be the same as that of an x-ray photon with a wavelength of 0. 85 nm?

Answer 1

Speed must an electron have if its momentum is to be the same as that of an x-ray photon with a wavelength of 0. 85 nm is 8.6*10^5m/s.

To find the answer, we have to know about the energy of photon.

What is the speed of the electron here?

• As we know that the momentum of an x-ray photon with a wavelength w,

                            $P=\frac{h}{w}$

where; h is the plank's constant.

• Thus, the momentum will be,

            $P=\frac{6.63*10^{-34}}{0.85*10^{-9}} =7.8*10^{-25}kgm/s.$

• We have to find the speed of the electron, thus, we have the expression of linear momentum as,

                          $P=mv\\v=\frac{P}{m} =\frac{7.8*10^{-25}}{9.1*10^{-31}}=8.6*10^5m/s.$

Thus, we can conclude that, speed must an electron have if its momentum is to be the same as that of an x-ray photon with a wavelength of 0. 85 nm is 8.6*10^5m/s.

Learn more about the energy of photon here:

brainly.com/question/3584036

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