Question

The speed of sound in an ideal gas is given by the relationship v = γRTM−−−−√ , where R - the universal gas constant = 8.314 J/mol⋅K ; T - the absolute temperature; M - the molar mass of the gas in kg/mol ; and γ is a characteristic of the specific gas. For air, γ = 1.4. Calculate the speed of sound in the air. Assume that air is 20% oxygen and 80% nitrogen and the temperature of air is 293 K . Express your answer to two significant figures and include the appropriate units.
Part B

While camping, you record a thunderclap whose intensity is 10−2 W/m2 . The clap reaches you 3.0 s after a flash of lightning. Assume that the thunder radiates spherically from its source. Estimate the total acoustical power generated by the bolt of lightning. Express your answer to two significant figures and include the appropriate units.

Answer 1

Answer:

Explanation:

1.) $v=\sqrt{\frac{yRT}{m} } \\\\=\sqrt{\frac{1.4\times8.3\times293}{0.029} }\\\\=342.64m/s$

2.) $4\pi r^2I=P\\\\\\P=4\pi(vt)^2I=4\pi (342.64\times3)^2(10^{-2})=1.33\times10^5watt$