Question

The first excited state of hydrogen atom is 10.2 eV above its ground state. The temperature needed to excite hydrogen atoms to first excited level, is :

• A. $ =\frac{n\times \frac{1}{2}m{{\upsilon }^{2}}}{t} $
• B. $ =\frac{360\times \frac{1}{2}\times 2\times {{10}^{-2}}\times {{(100)}^{2}}}{60} $
• C. $ g=\frac{Gm}{{{R}^{2}}} $
• D. $ \overrightarrow{\text{F}}=\left( \text{2\hat{i}}+\text{4\hat{j}} \right) $

Answer 1

Answer: (A)

According to kinetic interpretation of temperature $ {{t}_{1}}=5s,a=? $ Given : $ a=\frac{{{s}_{2}}-{{s}_{1}}}{{{t}^{2}}}=\frac{65-40}{{{(5)}^{2}}} $ So, $ =\frac{25}{25}=1m/{{s}^{2}} $ Or $ {{s}_{1}}=ut+\frac{1}{2}a{{t}^{2}} $ $ 40=5u+\frac{1}{2}\times 1\times 25 $ $ 5u=27.5\,\,or\,\,\,u=5.5m/s $