Answer:
Light comes in different colors like radio, ultra violet, gamma-ray, etc, and they are invisible to the bare eye
Explanation:
Answer:
v = 57.2 m/s
Explanation:
The average velocity of the train can be defined as the total distance covered by the train divided by the time taken by the train to cover that distance. Therefore, we will use the following formula to find the average velocity of the train:
v = s/t
where,
s = distance covered = 460 km = (460 km)(1000 m/1 km) = 4.6 x 10⁵ m
t = time taken to cover the distance = 2 h 14 min
Now, we convert it into minutes:
t = (2 h)(60 min/1 h) + 14 min
t = 120 min + 14 min = (134 min)(60 s/1 min)
t = 8040 s
Therefore, the value of velocity will be:
v = (4.6 x 10⁵ m)/8040 s
<u>v = 57.2 m/s</u>
Answer:
A police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase.
Explanation:
In Physics, Doppler effect can be defined as the change in frequency of a wave with respect to an observer in motion and moving relative to the source of the wave.
Simply stated, Doppler effect is the change in wave frequency as a result of the relative motion existing between a wave source and its observer.
The term "Doppler effect" was named after an Austrian mathematician and physicist known as Christian Johann Doppler while studying the starlight in relation to the movement of stars.
<em>The phenomenon of Doppler effects is generally applicable to both sound and light. </em>
An example of the Doppler effect is a police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase. This is so because when a sound object moves towards you, its sound waves frequency increases, thereby causing a higher pitch. However, if the sound object is moving away from the observer, it's sound waves frequency decreases and thus resulting in a lower pitch.
<em>Other fields were the Doppler effects are applied are; astronomy, flow management, vibration measurement, radars, satellite communications etc. </em>
Answer:
527 Hz
Solution:
As per the question:
Beat frequency of the player, 
Frequency of the tuning fork, f = 523 Hz
Now,
The initial frequency can be calculated as:
when
when
But we know that as the length of the flute increases the frequency decreases
Hence, the initial frequency must be 527 Hz
<h2>Question</h2>
why freezer is made in the upper part of refrigrator
<h2>✒ Answer</h2>
the cold air produced from it is denser than the warmer air in the bottom
<h3>Explaination</h3>
Freezer is normally provided at the top of the refrigerator, because density of the cold air is high compared to the hot air. In a refrigerator the air contacts with the cooling coil and gets cooling.Because of the high density the cold air gets down and the warm air/hot air moves upward and gets cooling from the cooling coil/evaporator coil. This process is repeated. If the Freezer is provided at the bottom place of the refrigerator, the cold air can't to move full area of the refrigerator. So the freezer is normally provided at the top at the refrigerator
