Answer:
The value is
Explanation:
From the question we are told that
The slit separation is 
The distance of the screen is 
The order of fringe is n = 7
The path difference is 
Generally the path difference is mathematically represented as

=> 
=> 
=> 
=>
=>
Answer:
1 km
Explanation:
= Gap between antennas = 600 m
= Frequency = 1 MHz
= Distance to receiver = 2 km
c = Speed of light = 
Wavelength is given by

Distance to be moved is given by

The distance to be moved is 1 km north.
The speed will increase four (4) times when the frequency of sound wave is increased four (4) times.
<h3>How to calculate the
frequency of a
wave.</h3>
Mathematically, the frequency of a sound wave is given by this formula:

<u>Where:</u>
- F is the frequency of a sound wave.
- V is the velocity of a sound wave.
is the wavelength of a sound wave.
<u>Note:</u> The frequency of the sound wave is increased four (4) times.
Substituting the given parameters into the formula, we have;

Therefore, the speed will increase four (4) times when the frequency of sound wave is increased four (4) times.
Read more on sound wave here: brainly.com/question/19250621