Question

The wavelength of a photon is $5000\mathring{A}$.Its momentum will be:

• A. $1.32\times {10}^{-27}kg\times$ meter/sec
• B. $1.5\times {10}^{-27}kg\times$ meter/sec
• C. $2.32\times {10}^{-27}kg\times$ meter/sec
• D. $5\times {10}^{-27}kg\times$ meter/sec

Answer 1

The correct option is A $1.32\times {10}^{-27}kg\times$ meter/sec

$\begin{array}{cc}& \lambda =\frac{n}{p}\\ \therefore P& =\frac{h}{\lambda }(P=\text{momentum})\\ P& =\frac{6.62\times {10}^{-34}}{5000\times {10}^{-10}}\\ P& =\frac{6.62}{5}\times {10}^{-27}\\ P& =1.32\times {10}^{-27}kg-meter\mid sec\end{array}$