Your answers for a), b), and c) are correct. Good work !
d). The high noise levels in Technology and PE are more of
a concern to the teachers than to the students because the
students are only in there for 1 or 2 periods a day, but the
Technology and PE teachers are in there ALL day.
e). Mr. Jones can't hear as high frequency as Jenny can because
he is much older than Jenny is. Sadly, even without damage due to
loud noise, the ability to hear high frequencies does decrease with age.
f). The wooden surfaces in the gym cause the gym to be louder
than it would be if it had carpet on the floor. Carpet ... and soft
walls and ceilings ... absorb a lot of the sound that hits them.
But hard surfaces don't absorb much of the sound that hits them,
so it just keeps bouncing around until it finally fades away.
You can see this easily ... just go into the gym at your school, clap
your hands once, and notice how long you keep hearing the sound
after you clap.
When a wave and/or the observer are moving, the frequency changes according to the Doppler Effect.
When the source is at rest and the observer moves away from it, the wave looks slower and its velocity will be:
v' = vsound - vobserver
In this case,
f₁ = v'/λ = (vsound - vobserver) / λ = f₀ · (<span>vsound - vobserver) / vsound
= f</span>₀ · (1 - vobserver/vsound)
On the contrary, when the source is moving away from an observer at rest, the wave appears with a different wavelengh:
λ' = (vsound + vsource) / f₀
In this case,
f₂ = v/<span>λ' = vsound / ((vsound + vsource) / f₀)
= </span>f₀ ·
![\frac{1}{1 + (vsource/vsound)}](https://tex.z-dn.net/?f=%20%5Cfrac%7B1%7D%7B1%20%2B%20%28vsource%2Fvsound%29%7D%20)
Now, let's put together these two cases:
f' = v' / <span>λ' =
= </span>
![\frac{vsound - vobserver}{ \frac{vsound + vsource}{f_{0} } }](https://tex.z-dn.net/?f=%20%5Cfrac%7Bvsound%20-%20vobserver%7D%7B%20%5Cfrac%7Bvsound%20%2B%20vsource%7D%7Bf_%7B0%7D%20%7D%20%7D%20)
<span>
= f</span>₀ ·
![\frac{vsound - vobserve}{vsound + vsource}](https://tex.z-dn.net/?f=%20%5Cfrac%7Bvsound%20-%20vobserve%7D%7Bvsound%20%2B%20vsource%7D%20)
= f<span>₀ · </span>
Answer:
![dQ=-500J](https://tex.z-dn.net/?f=dQ%3D-500J)
Explanation:
We have given work is done on the gas is 1200 J
So work done will be
( as work is done on the gas )
It is given that internal energy is increases by exactly 700 J
So ![dU=700J](https://tex.z-dn.net/?f=dU%3D700J)
From thermodynamic equation ![dQ=dU+dW](https://tex.z-dn.net/?f=dQ%3DdU%2BdW)
So ![dQ=700-1200=-500J](https://tex.z-dn.net/?f=dQ%3D700-1200%3D-500J)
Here negative sign indicates that heat flow out of the gas
If heat was negative then heal was flowing in the gas
Answer:
lungs, bronchi, trachea, larynx, pharynx, and nose.
Explanation:
The important parts of the respiratory system are lungs, bronchi, trachea, larynx, pharynx, and nose.
The respiratory system helps in bringing in oxygen in our body and taking out carbon dioxide from our body.