Question

(a) If the wavelength of an electron is 4.94 ✕ 10−7 m, how fast is it moving? km/s (b) If the electron has a speed equal to 5.60 ✕ 106 m/s, what is its wavelength? m Submit Answer 10.–/10 points SerCP11 28.2.P.001. Ask Your Teacher My Notes

Answer 1

(a) 1.468 km/s

(b) 129.5 m

Step-by-step explanation:

Use the formula for the wavelength is given by

`\lambda = (h)/(mv)`

mass of electron, m = 9.1 x 10^-31 kg

(a) λ = 4.94 x 10^-7 m

`\lambda = (h)/(mv)`

`v = (6.6* 10^(-34))/(9.1* 10^(-31)* 4.94* 10^(-7))`

v = 1.468 x 10^3 m/s = 1.468 km/s

(b) v = 5.60 x 10^6 m/s

`\lambda = (h)/(mv)`

`\lambda  = (6.6* 10^(-34))/(9.1* 10^(-31)* 5.60* 10^(6))`

λ = 129.5 m