Question

Helium (density 0.18 kg/m^3 at 0°C and 1 atm pressure) remains a gas until the extraordinarily low temperature of 4.2 K.What is the speed of sound in helium at 8 K?

Answer 1

`166.6396m/sec`

Step-by-step explanation:

Molar mass of helium =
`4* 10^(-3)kg/mole`

`\gamma` for helium is 1.67

The velocity of helium in sound at any temperature is given by
`v=\sqrt{(\gamma RT)/(M)}=\sqrt{(1.67* 8.314* 8)/(4* 10^(-3))}=166.6396m/sec`

R is a constant 8.314
`atm\ mol^(-1)K^(-1)`