Answer:

Explanation:
A number can be written in the form of :

Where
m is the real number
n is any integer
In this case, the average distance from the Sun to the Earth is given,
d = 150000000000 meters
There are 10 zeroes in this number. We need to write this number in scientific notation. It is given by :

So, the average distance from the Sun to the Earth is
. Hence, this is the required solution.
Answer:
The phase difference is
Explanation:
From the question we are told that
The distance between the loudspeakers is 
The distance of the listener from the wall 
The frequency of the loudspeakers is 
The velocity of sound is 
The path difference of the sound wave that is getting to the listener is mathematically represented as

Substituting values


The phase difference is mathematically represented as
= 
Where
is the wavelength which is mathematically represented as

substituting value


Substituting value into the equation for phase difference
= 
Answer:
D. Frequency
Explanation:
The energy of an electromagnetic wave is proportional to frequency, mathematically it is expressed as;
E ∝ f
E = hf
where;
h is Planck's constant = 6.626 x 10⁻³⁴ Js
The equation above can also be expanded to;

where;
c is speed of light = 3 x 10⁸ m/s
λ is the wavelength of the electromagnetic wave
Since the speed of light is constant, we can conclude that the energy of the electromagnetic wave is directly proportional to its frequency and inversely proportional to its wavelength.
Therefore, the correct option for direct proportionality is FREQUENCY
Tapping means the maximum use of the energy by the people.
<h3>What is energy?</h3>
The energy is the ability to do work.
The energy that can be tapped is solar energy. There are many ways developed to tap the solar energy and make the best use of it by solar plant, water heating, cooking, etc.
Thus, tapping means the maximum use of the energy by the people.
Learn more about tapping.
brainly.com/question/18623323
#SPJ4
Answer:
The energy in its ground state is 10 meV.
Explanation:
It is given that,
The energy of the electron in its first excited state is 40 meV.
Energy of the electron in any state is given by :

For ground state, n = 1
.............(1)
For first excited state, n = 2
.............(2)
Dividing equation (1) and (2), we get :


So, the energy in its ground state is 10 meV. Hence, this is the required solution.