Molecular Speeds: Dust particles in a grain elevator frequently have masses of the order of 1.0 × 10-9 kg. If, to a first approximation, we model the dust particles as an ideal gas, what would be the rms speed of such a particle in air at 27°C? The Boltzmann constant is 1.38 × 10-23 J/K.

A. 3.5 × 10-6 m/s
B. 5.6 × 10-5 m/s
C. 7.8 × 10-4 m/s
D. 5.2 × 10-3 m/s
E. 4.9 × 10-2 m/s


Answer: A

Physics & Space Science

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