There's no such thing as "stationary in space". But if the distance
between the Earth and some stars is not changing, then (A) w<span>avelengths
measured here would match the actual wavelengths emitted from these
stars. </span><span>
</span><span>If a star is moving toward us in space, then (A) Wavelengths measured
would be shorter than the actual wavelengths emitted from that star.
</span>In order to decide what's actually happening, and how that star is moving,
the trick is: How do we know the actual wavelengths the star emitted ?
<span>Answer:
Using 1/f = 1/d' + 1/d ...(where d' object distance and d is image distance)
1/4 = 1/7 + 1/d
1/4 - 1/7 = 1/d
3/28 = 1/d
d = 28/3
d = 9.33 cm</span>
Answer:
The minimum inductance needed is 2.78 H
Explanation:
Given;
frequency of the AC, f = 26.5 Hz
the root mean square voltage in the circuit,
= 41.2 V
the maximum current in the circuit, I₀ = 126 mA
The root mean square current is given by;

The inductive reactance is given by;

The minimum inductance needed is given by;

Therefore, the minimum inductance needed is 2.78 H
Your answer is going to be Appellate jurisdiction.
If i was feeling harsh today, I'd say the answer to your question is impossible to obtain due to the fact that photons do not emit radiation, photons ARE the radiation emitted. Though for the sake of it, here is the method...
<u>The simple method:
</u>
E=hf
therefore f=e/h
f=(3.611x10^-15) / 6.63x10^-34)
Answer: 5.45x10^18