The frequency of the wave is 6800 Hz
<u>Explanation:</u>
Given:
Wave number, n = 20
Speed of light, v = 340 m/s
Frequency, f = ?
we know:
wave number = 

Therefore, the frequency of the wave is 6800 Hz
Twenty is the atomic number of potassium.
Answer:
9. The Sun's Gravity
10. The core is the densest layer
By Considering the vertical distance and both vertical and horizontal final velocity, the time t = 0.45 s and Velocity V = 6.7 m/s
Given that a Veggie meatball with v = 5.0 m/s rolls off a 1.0 m high table.
Height h = 1.0 m
As the ball rolls off the table, it will be fallen under gravity. Where
g = 9.8 m/
Initial vertical velocity
= 0
Initial horizontal velocity
= 5 m/s
Considering the vertical distance, the formula to use to calculate the time will be;
h = ut + 1/2g
1 = 0 + 1/2 x 9.8
1 = 4.9
= 1/4.9
t = 
t = 0.45 seconds
It takes 0.45 seconds to hit the floor if no one sneezes.
To calculate its velocity when it hits the floor, we will need to calculate for both vertical and horizontal final velocity and find the resultant velocity of the two.
Vertical component
=
+ gt
= 0 + 9.8(0.45)
= 4.41 m/s
Horizontal component
=
+ at
but a = 0
= 5 m/s
Final velocity V = 
V = 6.67 m/s
Therefore, it will hit the floor at a velocity of 6.7 m/s
Learn more here: brainly.com/question/5063616
<span>Electromagnetic waves differ fundamentally from either water or sound waves because they does not require any medium, they can travel in free space (vacuum)
Hope this helps!</span>