Question

A one dimensional gas is a hypothetical gas with molecules that can move along only a single axis. The following table gives four situations, the velocities in metre per second of such a gas having four molecules. The plus and minus sign refer to the direction of the velocity along the axis.

In which situation root-mean-square speed of the molecules is greatest ?

• A. a
• B. b
• C. c
• D. d

Answer 1

Answer: (B)

b

Answer 2

V_rms =

Like V_rms =$\sqrt { \frac { ( - 2 ) ^ { 2 } + 3 ^ { 2 } + ( - 4 ) ^ { 2 } + 5 ^ { 2 } } { 4 } }$

=$\sqrt { \frac { 54 } { 4 } }$

It can be seen that V_rms for b is highest.