A straight horizontal tube closed at one end contains air ( , )

PHYSICS · Multi-part · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics

Problem

A straight horizontal tube closed at one end contains air (

\gamma = 1.4

M = 29\,\text{g mol}^{-1}

). From the open end a sharp sound pulse is produced, and the echo from the closed end is detected. At

300\,\text{K}

the echo is received

0.180\,\text{s}

after the pulse; after uniformly heating the air to

360\,\text{K}

the echo time becomes

0.165\,\text{s}

. (a) Part 1: (a) Determine the length of the tube. (b) Part 2: (b) Predict the echo time when the air in the tube is cooled to

240\,\text{K}