Consider a container of gas with 1200 molecules. The speed distribution of the molecules is as follows:
- 800 molecules with speed - 300 molecules with speed
100 molecules with speed
Find the average speed and the root mean square (rms) speed of the gas molecules.
Step 1: Calculate the total number of molecules
Step 2: Calculate the average speed
(number of molecules with speed $
) ;
;
( number of molecules with speed
) ;
;
(number of molecules with speed
) ;
Calculate the numerator
Numerator
Step 3: Calculate the mean square speed
Calculate the numerator
Numerator
Step 4: Calculate the root mean square (rms) speed
rms speed
Answer:
The average speed of the gas molecules is approximately , and the root mean square (rms) speed is approximately
.