Skip to main content

What is the speed of sound in a perfectly rigid rod? What is the speed of sound in free space?

Sound is a longitudinal wave and needs a medium to transmit from one location to another. In air, the sound travels by compression and rarefaction of air in the direction of wave motion. In other words, the air molecules move back and forth (which causes compression and decompression of air pockets) in the direction of the sound wave and this causes them to transmit from one location to another. That is, in the simplest terms,...

Sound is a longitudinal wave and needs a medium to transmit from one location to another. In air, the sound travels by compression and rarefaction of air in the direction of wave motion. In other words, the air molecules move back and forth (which causes compression and decompression of air pockets) in the direction of the sound wave and this causes them to transmit from one location to another. That is, in the simplest terms, sound cannot travel in the absence of a medium.


Thus, in free space (or a vacuum), the speed of sound is zero. This is because there is no medium to transmit the sound wave.


In comparison, in the case of a perfectly rigid rod, there is no free atom or molecule and all the particles move as a single body. Thus, the sound would be transmitted instantly from the rigid body and hence the speed of sound through a rigid body is infinite. Another way to understand this scenario is by mathematical formulation of the speed of sound, which is:


`c = sqrt(E/rho)`


Here, c is speed of sound, E is modulus of elasticity (ratio of stress and strain) and `rho` is density. Since strain is zero for a rigid body (no change in length), E is infinite for a rigid body and so is the speed of sound through it.


Hope this helps. 


Comments

Post a Comment

Popular posts from this blog

What is hyperbole in the story "The Gift of the Magi" by O. Henry?

The most obvious use of hyperbole in "The Gift of the Magi" occurs when the narrator describes Della's and Jim's evaluations of their two treasures—her long, luxuriant hair and his gold watch. Had the Queen of Sheba lived in the flat across the airshaft, Della would have let her hair hang out the window some day to dry just to depreciate Her Majesty's jewels and gifts. Had King Solomon been the janitor, with all his... The most obvious use of hyperbole in "The Gift of the Magi" occurs when the narrator describes Della's and Jim's evaluations of their two treasures—her long, luxuriant hair and his gold watch. Had the Queen of Sheba lived in the flat across the airshaft, Della would have let her hair hang out the window some day to dry just to depreciate Her Majesty's jewels and gifts. Had King Solomon been the janitor, with all his treasures piled up in the basement, Jim would have pulled out his watch every time he passed, just to see him plu
Post a Comment
Read more

How can I analyze Moon and Six Pence by Somerset Maugham?

In "Moon and Sixpence," loosely based on the life of Paul Gaugin, Maugham presents a study of the tension between the "civilized" life of 19th century Europe, and the lead character's desire to throw off the shackles of bourgeois life. Charles Strickland is a middle-aged English stockbroker with a wife and family. By abandoning his domestic life, Strickland commits what many in European society would consider a gross betrayal of one of the foundations of... In "Moon and Sixpence," loosely based on the life of Paul Gaugin, Maugham presents a study of the tension between the "civilized" life of 19th century Europe, and the lead character's desire to throw off the shackles of bourgeois life. Charles Strickland is a middle-aged English stockbroker with a wife and family. By abandoning his domestic life, Strickland commits what many in European society would consider a gross betrayal of one of the foundations of that society. His decision to e
Post a Comment
Read more

What are some literary devices in Macbeth, Act V, Scene 1?

Act V, Scene i of Macbeth certainly continues the imagery that is prevalent in the play with its phantasmagoric realm, as in this scene a succession of things are seen or imagined by Lady Macbeth. Imagery - The representation of sensory experience Lady Macbeth imagines that she sees bloody spots (visual imagery) on the stairs; she also smells blood (olfactory imagery): Here's the smell of the blood still. All the perfumes of Arabia will not... Act V, Scene i of Macbeth certainly continues the imagery that is prevalent in the play with its phantasmagoric realm, as in this scene a succession of things are seen or imagined by Lady Macbeth. Imagery - The representation of sensory experience Lady Macbeth imagines that she sees bloody spots (visual imagery) on the stairs; she also smells blood (olfactory imagery): Here's the smell of the blood still. All the perfumes of Arabia will not sweeten this little hand. Oh! oh, oh! (5.1.53-55) Hyperbole - Obvious exaggeration  There is also h
Post a Comment
Read more