Answer:
The distance from the radio station is 0.28 light years away.
Solution:
As per the question:
Distance, d = 4 ly
Frequency of the radio station, f = 854 kHz = 
Power, P = 50 kW = 

Now,
From the relation:
P = nhf
where
n = no. of photons/second
h = Planck's constant
f = frequency
Now,

Area of the sphere, A = 
Now,
Suppose the distance from the radio station be 'r' from where the intensity of the photon is 



Now,
We know that:
1 ly = 
Thus

Answer:
Mass of the sled in the snow 83.33 kg.
<u>Explanation</u>:
Given that,
Force applied to move the sled in the snow (F) = 75N

We know that
Newton's second law of motion is

F = ma (Or "force" is equal to "mass" times "acceleration".)
So if we move this around we can isolate mass and get mass


M = 83.33 kg
Mass of the sled in the snow <u>83.33 kg.</u>
Answer: lift force = 100sin60 = 86.6 N
pull force = 100sin60 = 50.0 N
Explanation:
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>