Helium gas occupies a volume of 0.04m^3 at a pressure of 2*10^5 N/m^2 and a temperature of 300K,calculate:

Question

1.) the mass of helium
2.)the root mean square speed of its molecule
3.)the root mean square speed at 432K when the gas is heated at constant pressure to this temperature

Answer 1

The answer for the question

Answer 2

I didnt get the answer