Question

The r.m.s. speed of a group of 7 gas molecules having speeds (6, 4, 2, 0, – 2, – 4, – 6) m/s is

• A. 1.5 m/s
• B. 3.4 m/s
• C. 9 m/s
• D. 4 m/s

Answer 1

Answer: (D)

4 m/s

Answer 2

$v_{rms} = \sqrt{\frac{(6)^{2} + (4)^{2} + (2)^{2} + (0)^{2} + ( - 2)^{2} + ( - 4)^{2} + ( - 6)^{2}}{7}}$

$= 4m/s.$