Answer:
The order of increasing energy is as follows
"microwave < infrared < visible < ultraviolet"
Option (A) is correct.
Explanation:
Given:
Arrange the following spectral regions in order of increasing energy: infrared, microwave, ultraviolet, visible.
From the formula of energy in terms of frequency.
Where 
planck constant, 
frequency of light.
From above formula we can conclude that higher frequency means higher energy.
In our case ultraviolet has higher frequency and microwave has lower frequency.
So ultraviolet has higher energy and microwave has lower energy.
microwave < infrared < visible < ultraviolet
Therefore, the order of increasing energy is as follows
"microwave < infrared < visible < ultraviolet"
Answer:
L = 2.8 cm
Explanation:
Period T = 4 / 12 = 1/3 s
T = 2π√(L/g)
L = (T/2π)²g
L = ((1/3)/2π)²9.8 = 0.02758... ≈ 2.8 cm
Since the frequency of sound in a medium is constant, therefore, the concert-goers would hear the low notes and high notes at the same time.
<h3>What is a dispersive medium?</h3>
A dispersive medium is a medium which spreads out or disperses a substance passing through it.
Since CO2 is a dispersive medium, it means sound waves passing through it would be dispersed based on wavelength.
The note of a sound depends on its frequency, the higher the frequency, the higher the note.
Frequency of sound is constant, therefore, the concert-goers would hear the low notes and high notes at the same time.
Learn more about dispersion of sound at: brainly.com/question/781734
