题目内容：

SAT2物理题,貌似是有关理想气体的.
直接原题了.
A sample of an ideal gas is heated,doubling its absolute temperature.which of the fllowing statements best describs the result of heating the gas
A.The root-mean-square speed of the gas molecules doubles.
B.The averange kinetic energy of the gas molecules increases by a factor of √2(根号2).
C.The averange kinetic energy of the gas molecules increases by a factor of 4
D.The speeds of the gas molecules cover a wide rang,but the root-mean-square speed increas by a factor of √2(根号2).
E.The speeds of the gas molecules cover a wide rang,but the root-mean-square speed increas by a factor of 2.
貌似有关于理想气体,但是这个用什么公式算?
另外这个The root-mean-square speed of the gas molecules