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)

$=\frac{n\times \frac{1}{2}m{{\upsilon }^{2}}}{t}$

Answer 2

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 ${{s}_{1}}=ut+\frac{1}{2}a{{t}^{2}}$ $40=5u+\frac{1}{2}\times 1\times 25$ $5u=27.5\,\,or\,\,\,u=5.5m/s$