Question

With what velocity must an electron travel so that its momentum is equal to that of a photon of wavelength 560nm?

Answer 1

Uncertainly theory Heinsberg

Known:
λ=560 nanometer=560 x 10⁻⁹ m
Asked: momentum(p) and velocity(v)?
Answer:
Remeber that :
constant plank (h) :6,6 x 10⁻³⁴ Js
mass of electron (m)=9,1 x 10⁻³¹ kg

So
Δp≥ h 
        λ
     ≥ 6,6 x 10⁻³⁴
         560x10⁻⁹
     ≥ 1,17 x 10⁻²⁷ kgm/s

and:
m.v=p
so
    v= p 
         m
      =1,17 x 10⁻²⁷
         9,1 x 10⁻³¹
      =1,2 x 10⁻⁴ m/s

#Adam

Answer 2

energy of an accelerated electron = QV

                                                         = 1.602 *$10{2}$ * 4.5

                                                        = 7.209 * $10^{-19}$

   hc$\pi$= 7.209 * $10^{-19}$

  $\pi$= 7.209 * $10^{-19}$÷ 6.6 * $10^{-34} *3*10^{8}$

$\pi$= 3.63 * $10^{6$m ^-1

hope this answer helps....