Question

4. A closed vessel of fixed volume contains a
mass m of an ideal gas, the root mean square
speed being v. Additional mass m of the same
gas is pumped into the vessel and the pressure
rises to 2p, the temperature remaining the same
as before. The root mean square speed of the
molecules now is
V
1) 52
2) vv2
3) 2V
4)V​

Answer 1

Answer:

I am in 7th std and you are asking 10th std question

Answer 2

Answer:

given = ideal gas , fixed volume , mass =m

            pressure = p

to find = root mean square speed

solution ,

PV  =  m / M RT

P"V = 2m/ MRT , P" /P= 2

Vrms = $\sqrt{\frac{3p}{p} } = \sqrt{ \frac{3P}{m/ V} \\\\v"rms = \sqrt{\\\frac{3p"}{2m/V} \\ \sqrt\frac{3(2p)}{2(m/V)} \\\\ = \sqrt{frac{3p}{m/V} = vrms = v$

so we can choose the option 4 v

as a correct answer .