Answer:
frequency
Explanation:
The phenomenon of apparent change in frequency due to the relation motion between the source and the observer is called Doppler's effect.
So, when we move farther, the frequency of sound decreases. The formula of the Doppler's effect is

where, v is the velocity of sound, vs is the velocity of source and vo is the velocity of observer, f is the true frequency. f' is the apparent frequency.
Answer:
Acceleration of the crate is 0.362 m/s^2.
Explanation:
Given:
Mass of the box, m = 40 kg
Applied force, F = 15 N
Angle at which the force is applied,
= 15°
We have to find the magnitude of the acceleration.
Let the acceleration be "a".
FBD is attached with where we can see the horizontal and vertical component of force.
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and ⇒ 
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⇒ Applying concept of forces.
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<em> ...Newtons second law Fnet = ma</em>
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⇒ Plugging the values.
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<em>...f is the friction which is zero here.</em>
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Magnitude of the acceleration of the crate is 0.362 m/s^2.
A large elliptical galaxy. Hope this helped
Solar because it is transfered through light
B. Frequency remains unchanged because the energy in a photon is E=hf. So if the frequency changes so does the energy and that doesn't happen to EM waves entering a medium by the conservation of energy