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A pipe of length 1.5 m closed at one end...

A pipe of length 1.5 m closed at one end is filled with a gas and it resonates at `30^(@)C` in its fundamental with a tuning fork. Another pipe of the same length but open at both ends and filled with air and it resonates in its fundamental with the same tuning fork. Calculate the velocity of sound at `0^(@)C` in the gas, given that the velocity of sound in air is `360 m s^(-1)` at `30^(@)`.

A

`580 m//s`

B

`683 m//s`

C

`880 m//s`

D

`743 m//s`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we will follow these steps: ### Step 1: Understand the resonance conditions We have two pipes: 1. A pipe closed at one end (let's call it Pipe 1). 2. A pipe open at both ends (let's call it Pipe 2). Both pipes have the same length, \( L = 1.5 \, \text{m} \). ### Step 2: Determine the fundamental frequency for each pipe - For a pipe closed at one end, the fundamental frequency is given by: \[ f_1 = \frac{v_g}{4L} \] where \( v_g \) is the velocity of sound in the gas. - For a pipe open at both ends, the fundamental frequency is given by: \[ f_2 = \frac{v_a}{2L} \] where \( v_a \) is the velocity of sound in air. ### Step 3: Set the frequencies equal Since both pipes resonate with the same tuning fork, we have: \[ f_1 = f_2 \] This implies: \[ \frac{v_g}{4L} = \frac{v_a}{2L} \] ### Step 4: Simplify the equation We can cancel \( L \) from both sides: \[ \frac{v_g}{4} = \frac{v_a}{2} \] Multiplying both sides by 4 gives: \[ v_g = 2v_a \] ### Step 5: Substitute the known value We know that the velocity of sound in air at \( 30^\circ C \) is \( v_a = 360 \, \text{m/s} \): \[ v_g = 2 \times 360 = 720 \, \text{m/s} \] ### Step 6: Calculate the velocity of sound at \( 0^\circ C \) The velocity of sound in gases is proportional to the square root of the temperature in Kelvin. Therefore, we can use the formula: \[ \frac{v_1}{v_2} = \sqrt{\frac{T_1}{T_2}} \] where: - \( v_1 \) is the velocity of sound at \( 0^\circ C \) (which we need to find), - \( v_2 \) is the velocity of sound at \( 30^\circ C \) (which we found to be \( 720 \, \text{m/s} \)), - \( T_1 = 273 \, \text{K} \) (temperature at \( 0^\circ C \)), - \( T_2 = 303 \, \text{K} \) (temperature at \( 30^\circ C \)). ### Step 7: Substitute the values into the equation \[ \frac{v_1}{720} = \sqrt{\frac{273}{303}} \] Now, solving for \( v_1 \): \[ v_1 = 720 \times \sqrt{\frac{273}{303}} \] ### Step 8: Calculate \( \sqrt{\frac{273}{303}} \) Calculating the square root: \[ \sqrt{\frac{273}{303}} \approx 0.952 \] Thus, \[ v_1 \approx 720 \times 0.952 \approx 685.44 \, \text{m/s} \] ### Step 9: Final answer Rounding to the nearest whole number, the velocity of sound at \( 0^\circ C \) in the gas is approximately: \[ v_1 \approx 683 \, \text{m/s} \] ### Conclusion The velocity of sound at \( 0^\circ C \) in the gas is \( 683 \, \text{m/s} \). ---
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