I think the correct answer from the choices listed above is the first option. The speed of a sound wave is slower than an electromagnetic wave or l<span>ight waves are </span><span>faster than sound waves. Hope this answers the question. Have a nice day.</span>
Answer:
D. n=6 to n=2
Explanation:
Given;
energy of emitted photon, E = 3.02 electron volts
The energy levels of a Hydrogen atom is given as; E = -E₀ /n²
where;
E₀ is the energy level of an electron in ground state = -13.6 eV
n is the energy level
From the equation above make n, the subject of the formula;
n² = -E₀ / E
n² = 13.6 eV / 3.02 eV
n² = 4.5
n = √4.5
n = 2
When electron moves from higher energy level to a lower energy level it emits photons;

For a photon to be emitted, electron must move from higher energy level to a lower energy level. The higher energy level is 6 while the lower energy level is 2
Therefore, The electron energy-level transition is from n = 6 to n = 2
Speed =dist./time
=73.4/5
=14.68 km/hr
Answer:
Part a)

Part b)

direction = downwards
Explanation:
As we know that the negative charge will experience the force due to some other charge below it
the force is given as

now we know that

now plug in all data



since this is a repulsion force so it must be a negative charge
Part b)
As per Newton's III law it will exert equal and opposite force on it
So here the force on the charge below it will be same in magnitude but opposite in direction
so here we have

direction = downwards