According to Kinetic theory,
Average kinetic energy of a gas molecule =21mvrms2=23kT
Thus, vrms=m3kT
At NTP, T=293K
Putting the values, we have
=5×10−173×1.38×10−23×293
≈15mms−1
The root mean square speed of smoke particles of mass 5×10−17kg in their Brownian motion in air at NTP is approximately.
[Given k=1.38×10−23JK−1]
Held on 29 Jul 2022 · Verified 6 Jul 2026.
60mms−1
12mms−1
15mms−1
36mms−1
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