WAEC - Physics (2020 - No. 41)
An electron of mass 9.1x 10\(^{-31}\) kg is travelling at a speed of 2.0 x 10\(^6\)ms\(^{-1}\). Calculate the associate wavelength of the electron. [h = 6.6. x 10\(^{-34}\) Js]
3.63 x10\(^{-10}\) m
3.63 x 10\(^{-8}\) m
3.63 x 10\(^{-7}\) m
6.89 x 10\(^{-4}\) m
Explanation
Using de Broglie wavelength formula: \(\lambda\) = \(\frac{h}{p}\)
P = momentum = mass x velocity = 9.1x 10\(^{-31}\) x 2.0 x 10\(^6\) = 1.82 × 10\(^{ −24}\) kg m/s
\(\lambda\) = \(\frac{6.6. \times 10^{-34}}{1.82 \times 10^{ −24}}\) = 3.63 x 10\(^{-10}\) m
Comments (0)
