Reading a book in your warm, comfy seat ... in Row-27 of a
passenger airliner cruising at 450 miles per hour.
Answer:
Feathers are great thermal insulators.
Explanation:
Feathers are great thermal insulators. The loose structure of down feathers traps air.
As a result, energy cannot be transmitted easily through down feathers. This means birds are insulated from cold air outside, plus their body heat doesn't escape easily either.
Human beings discovered that down feathers are good for insulation long ago. For example, documents from the 1600s show that Russian merchants sold “bird down" to the Dutch hundreds of years ago.
Today, down is used in all sorts of products, including coats, bedding, and sleeping bags, to help better insulate the user from cold weather. Down can be collected from many different types of birds, but most of today's supply comes from domestic geese.
If you have a down coat or comforter, is it all down? In the United States, laws require that products labeled “100 percent down" contain only down feathers.
If your product is labeled “down," it can contain a mixture of both down feathers and synthetic fibers. Not all down feathers are created equal, though.
Down insulation is rated on a measure called “fill power." The higher the fill power, the more the down insulates.
The highest fill-power rating — 1200 — goes to eiderdown, which comes from the Common Eider duck. Eiderdown tends to be expensive.
The 'Rite of Spring' was composed by Igor Stravinsky.
<h2>
Answer:0.048</h2>
Explanation:
Let the length of perihelion be 
Let the length of aphelion be 
Let the length of semi major axis of the elliptical path be 
As we know that semi major axis is the average of perihelion and aphelion.
So,
Let the eccentricity of the elliptical path be 
Answer:
The fundamental frequency and length of the pipe are 100 Hz and 1.7 m.
Explanation:
Given that,
Frequency f = 550 Hz
Frequency f' = 650 Hz
We know that,
AMT pipe is open pipe.
(b). We need to calculate the length of the pipe
Using formula of organ pipe
For 550 Hz,
...(I)
For 650 Hz,
...(II)
From equation (I) and (II)
(a). We need to calculate the fundamental frequency for n = 1
Using formula of fundamental frequency
put the value of L
Hence, The fundamental frequency and length of the pipe are 100 Hz and 1.7 m.
