Calculate the temperature at which sound travels in hydrogen with the same speed as in helium at N.T.P. The density of helium is twice that of hydrogen.

Explanation

To solve the problem of calculating the temperature at which sound travels in hydrogen with the same speed as in helium at normal temperature and pressure (N.T.P.), we can follow these steps:

### Step 1: Understand the relationship between speed of sound, temperature, and density
The speed of sound \( v \) in a gas can be expressed as:
\[ v = \sqrt{\frac{P}{\rho}} \]
where \( P \) is the pressure and \( \rho \) is the density of the gas. At N.T.P., the pressure is constant, so we can relate the speeds of sound in hydrogen and helium using their densities and the temperatures.
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