An electron moves with a speed of 2.0 x 10\(^6\)ms\(^{-1}\) in a straight line. Calculate the wavelength of the electron wave. [mass of an electron = 9.1 x 10\(^{-31}\) kg][Planck's constant = 6.6 x 10\(^{-34}\)Js]
A
3.63 x 10-10m
B
6.51 x 10-9m
C
4.24 x 10-8m
D
7.25 x 10-8m
Verified Correct Answer: A.
Physical Principles & Numerical Solution
\(\lambda = \frac{\text{h}}{\text{mv}}\)
mv = 9.1 \(\times 10^{-31} \times 2.0 \times 10^6 = 1.82 \times 10^{-24} \, \text{kg m/s}\)
\(\lambda = \frac{6.6 \times 10^{-34}}{1.82 \times 10^{-24}} = 3.63 \times 10^{-10} \, \text{m}\)
3.63 \times 10\(^{-10}\)
Source: Myschool Past Questions Archive (Record #35355)