Question

The velocity of the molecules of a gas at temperature 120K is $v$. At what temperature will the velocity be $2v$

• A. 120 K
• B. 240 K
• C. 480 K
• D. 1120 K

Answer 1

Answer: (C)

480 K

Answer 2

$v_{rms} \propto \sqrt{T} \Rightarrow \frac{v_{2}}{v_{1}} = \sqrt{\frac{T_{2}}{T_{1}}} \Rightarrow \frac{2}{1} = \sqrt{\frac{T_{2}}{T_{1}}}$

Ž $T_{2} = 2 \times 120 = 480K$