Force = mass times acceleration
F = 21000 x 36.9 = 774900
Therefore, 774900N force is required.
Answer:
The speed of the wave with a frequency 100 mhz will be 
Explanation:
We have given that frequency of light is 100 mhz
We have to find the speed of light in vaccuum
We know that all electromagnetic waves travels in vaccum wth the same speed as the speed of light
And we know that speed of light is equal to 
So the speed of the wave with a frequency 100 mhz will be 
Answer:

Explanation:
Given that,
A radio wave transmits 38.5 W/m² of power per unit area.
A flat surface of area A is perpendicular to the direction of propagation of the wave.
We need to find the radiation pressure on it. It is given by the formula as follows :

Where
c is speed of light
Putting all the values, we get :

So, the radiation pressure is
.
Answer:
Gravity
Explanation:
Gravity is a force that pulls the surface of the earth and keeps the planets in orbits around the sun.