Answer:

Explanation:
The electric field equation of a electromagnetic wave is given by:
(1)
- E(max) is the maximun value of E, it means the amplitude of the wave.
- k is the wave number
- ω is the angular frequency
We know that the wave length is λ = 700 nm and the peak electric field magnitude of 3.5 V/m, this value is correspond a E(max).
By definition:
And the relation between λ and f is:




The angular frequency equation is:


![\omega=2.69*10^{15} [rad/s]](https://tex.z-dn.net/?f=%5Comega%3D2.69%2A10%5E%7B15%7D%20%5Brad%2Fs%5D)
Therefore, the E equation, suing (1), will be:
(2)
For the magnetic field we have the next equation:
(3)
It is the same as E. Here we just need to find B(max).
We can use this equation:



Putting this in (3), finally we will have:
(4)
I hope it helps you!
Answer:
A and B
Explanation:
The relation between frequency and wavelength is shown below as:

c is the speed of light having value 
Thus, the product of the wavelength and the frequency is constant and equal to 
<u>Option A is correct.</u>
Given, Frequency = 
Thus, Wavelength is:



Also, 1 m =
Å
So,
<u>Wavelength = 3.0 Å</u>
<u>Option B is correct.</u>
As stated above, the speed of electromagnetic radiation is constant. Hence, each radiation of the spectrum travels with same speed.
<u>Option C is incorrect.</u>
Answer
given,
Tension of string is F
velocity is increased and the radius is not changed.
the string makes two complete revolutions every second
consider the centrifugal force acting on the stone
=
now centrifugal force is balanced by tension
T =
From the above expression we can clearly see that tension is directly proportional to velocity and inversely proportional to radius.
When radius is not changing velocity is increasing means tension will also increase in the string.
Answer:
22m/s
Explanation:
To find the velocity we employ the equation of free fall: v²=u²+2gh
where u is initial velocity, g is acceleration due to gravity h is the height, v is the velocity the moment it hits the ground, taking the direction towards gravity as positive.
Substituting for the values in the question we get:
v²=2×9.8m/s²×25m
v²=490m²/s²
v=22.14m/s which can be approximated to 22m/s