Answer: The correct answer is "trumpet".
Explanation:
Resonance occurs when the applied frequency on the object is equal to the natural frequency of the object.
Wind instruments use resonance in the air column to amplify the sound. It makes the sound louder. Sound is produced by using lips or vibrating reeds or buzzing sound into the mouthpiece.
Therefore, resonance in air column is used in trumpet musical instruments.
Answer:
The velocity of the man from the frame of reference of a stationary observer is, V₂ = 5 m/s
Explanation:
Given,
Your velocity, V₁ = 2 m/
The velocity of the person, V₂ =?
The velocity of the person relative to you, V₂₁ = 3 m/s
According to the relative velocity of two
V₂₁ = V₂ -V₁
∴ V₂ = V₂₁ + V₁
On substitution
V₂ = 3 + 2
= 5 m/s
Hence, the velocity of the man from the frame of reference of a stationary observe is, V₂ = 5 m/s
Answer:
The thrown rock will strike the ground 
earlier than the dropped rock.
Explanation:
<u>Known Data</u>
, it is negative as is directed downward
<u>Time of the dropped Rock</u>
We can use 
, to find the total time of fall, so 
, then clearing for 
.
![t_{D}=\sqrt[2]{\frac{300m}{4.9m/s^{2}}} =\sqrt[2]{61.22s^{2}} =7.82s](https://tex.z-dn.net/?f=t_%7BD%7D%3D%5Csqrt%5B2%5D%7B%5Cfrac%7B300m%7D%7B4.9m%2Fs%5E%7B2%7D%7D%7D%20%3D%5Csqrt%5B2%5D%7B61.22s%5E%7B2%7D%7D%20%3D7.82s)
<u>Time of the Thrown Rock</u>
We can use , to find the total time of fall, so 
, then, 
, as it is a second-grade polynomial, we find that its positive root is 
Finally, we can find how much earlier does the thrown rock strike the ground, so 
Answer:
The final temperature of the gas is <em>114.53°C</em>.
Explanation:
Firstly, we calculate the change in internal energy, ΔU from the first law of thermodynamics:
ΔU=Q - W
ΔU = 1180 J - 2020 J = -840 J
Secondly, from the ideal gas law, we calculate the final temperature of the gas, using the change in internal energy:
Then we make the final temperature, T₂, subject of the formula:
Therefore the final temperature of the gas, T₂, is 114.53°C.
The culture that gave the visiting Europeans eyeglasses and silk fabric was the Chinese civilization. The Chinese invented eyeglasses over a 1,000 years ago<span>, according to British scientist and historian Sir Joseph Needman. By the time Marco Polo arrived in China around 1270, eyeglasses (which he mentions in his accounts) were widely used in Chinese upper class. On the other hand, s</span>ilk has been used by the Chinese for approximately 5,000 years.<span> The earliest evidence of silk dates back to around 4,000-3,000 BC in Shanxi province, where a culture silk cocoon was found.</span>
