Speed of sound.Someone explain.

[Tashyboy]

https://www.bbc.co.uk/news/uk-england-london-51433720#share-tools

Quote,
Despite travelling faster than the speed of sound the plane would not have broken the sonic barrier as it was helped along by fast-moving air.

According to the news report the 747 hit speeds of 825 mph, with the speed of sound about 767 mph. So why did it not break the speed of sound.

It also quotes the planes travel at about 85% to the speed of sound. Would the shockwaves affect a passenger plane or not.

Thoughts from our golfing pilots and others please.

 

[Deleted member 15344]

The speed of the plane would be relative to the air around - so if the jet stream it’s using is fast then the planes relative speed to that air would be below the required 760mph needed to break the sound barrier

 

[SocketRocket]

https://www.bbc.co.uk/news/uk-england-london-51433720#share-tools

Quote,
Despite travelling faster than the speed of sound the plane would not have broken the sonic barrier as it was helped along by fast-moving air.

According to the news report the 747 hit speeds of 825 mph, with the speed of sound about 767 mph. So why did it not break the speed of sound.

It also quotes the planes travel at about 85% to the speed of sound. Would the shockwaves affect a passenger plane or not.

Thoughts from our golfing pilots and others please.

Concorde flew at twice the speed of sound but passengers on the plane would not hear the sonic boom as they were travelling faster than the speed of the sound thus leaving it behind.

 

[Blue in Munich]

825mph (speed of jet) - 767 mph (speed of sound in still air)= 58mph. If the jet stream is moving at 59mph or faster, then the jet never actually reaches the speed of sound. And if the jet reaches 825mph, you can bet the jetstream is faster than 59mph.

Don't fancy the journey back, they'll have to stop halfway to fill up.

 

[Blue in Munich]

https://www.sciencealert.com/a-powe...d-a-plane-to-a-top-speed-of-1-289-km-per-hour

 

[Crow]

825mph (speed of jet) - 767 mph (speed of sound in still air)= 58mph. If the jet stream is moving at 59mph or faster, then the jet never actually reaches the speed of sound. And if the jet reaches 825mph, you can bet the jetstream is faster than 59mph.

Don't fancy the journey back, they'll have to stop halfway to fill up.

It reaches the speed of sound (which Shirley is defined as being in still air and is a 767 mph constant?) but doesn't break the sound barrier, where it has to overtake the sound waves in the moving air.

 

[Tashyboy]

https://www.sciencealert.com/a-powe...d-a-plane-to-a-top-speed-of-1-289-km-per-hour

cheers BIM Explains it nice and clear.

 

[Blue in Munich]

It reaches the speed of sound (which Shirley is defined as being in still air and is a 767 mph constant?) but doesn't break the sound barrier, where it has to overtake the sound waves in the moving air.

It doesn't reach a speed equal to or in excess of the speed of sound relative to the speed of the air around it.

 

[Tashyboy]

It doesn't reach a speed equal to or in excess of the speed of sound relative to the speed of the air around it.

In essence the speed of sound is not still but moves. ??

 

[SwingsitlikeHogan]

In essence the speed of sound is not still but moves. ??

Everything is relative ?

 

[Tashyboy]

Everything is relative ?

Especially me aunties and uncles ?

 

[pendodave]

I guess it's similar to walking along inside a high speed train. You're walking at 5mph as far as you and the other passengers are concerned, but at 130 if I'm watching over the hedge...
It literally depends on your point of view.

 

[williamalex1]

Whoosh bang, sounds about right.

 

[Tashyboy]

I guess it's similar to walking along inside a high speed train. You're walking at 5mph as far as you and the other passengers are concerned, but at 130 if I'm watching over the hedge...
It literally depends on your point of view.

and for Tash, the penny has just dropped. ?

 

[Pathetic Shark]

If I throw a golf ball in the air, is it moving forwards? If I throw a golf ball in the air whilst on a train going at 100 mph, is it moving forwards?
The answer is the earth is moving at whatever speed round the sun so everything is moving even when you are standing still on the ground.

No wonder I hated physics at school - beam me up Scotty.

 

[Tashyboy]

If I throw a golf ball in the air, is it moving forwards? If I throw a golf ball in the air whilst on a train going at 100 mph, is it moving forwards?
The answer is the earth is moving at whatever speed round the sun so everything is moving even when you are standing still on the ground.

No wonder I hated physics at school - beam me up Scotty.

????

 

[Piece]

If I throw a golf ball in the air, is it moving forwards? If I throw a golf ball in the air whilst on a train going at 100 mph, is it moving forwards?
The answer is the earth is moving at whatever speed round the sun so everything is moving even when you are standing still on the ground.

No wonder I hated physics at school - beam me up Scotty.

And the Sun and Solar System are moving around the Milky Way black hole...and the Milky Way is moving around …. etc. etc.

 

[SwingsitlikeHogan]

If I throw a golf ball in the air, is it moving forwards? If I throw a golf ball in the air whilst on a train going at 100 mph, is it moving forwards?
The answer is the earth is moving at whatever speed round the sun so everything is moving even when you are standing still on the ground.

No wonder I hated physics at school - beam me up Scotty.

And when tracking a missile or rocket you launched - or someone else has and you are tracking it - you have to take into account the coriolis effect of the earth's rotation on your frames of reference - oooh - it makes the maths interesting

 

[Pathetic Shark]

So basically it means I hit my last drive about 220 yards on earth but about 65,000 miles in relative space. Yeah!!!

 

[SwingsitlikeHogan]

So basically it means I hit my last drive about 220 yards on earth but about 65,000 miles in relative space. Yeah!!!

Or backwards just as far...