There is too much information given, it's hard to understand exactly which variables are important in this problem.
Answer:

Explanation:
h = Planck's constant = 
m = Mass of electron = 
k = Coulomb constant = 
e = Charge of electron = 
n = 1 (ground state)
Angular momentum is given by

From Bohr's atomic model we have


The centripetal force will balance the electrostatic force

The diameter is 
To solve this problem we will apply the concepts related to equilibrium, for this specific case, through the sum of torques.

If the distance in which the 600lb are applied is 6in, we will have to add the unknown Force sum, at a distance of 27in - 6in will be equivalent to that required to move the object. So,



So, Force that must be applied at the long end in order to lift a 600lb object to the short end is 171.42lb
Answer:
a. 299,792,458 m/s
Explanation:
Since the speed of light in a vacuum is invariant and has the value of 299,792,458 m/s, we would measure this value of 299,792,458 m/s for the speed of light from the star as it arrives on Earth.
<span>A moving electrical charge produces a magnetic field and a moving magnetic field produces an electrical field. An electromagnet works by coiling a bunch of wire and spinning a couple of magnets around that wire at high speeds. When this occurs the magnets induce an electric current in the wire and hence the electricity production. Once the magnets stop spinning, the induced electrical field dissipates and the current stops flowing through the wire.
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