A, Lenz' Law. There need to be a difference of flux, so if you use AC you will get a current too.
Answer:
The answer is the principal Quantum number (n)
Explanation:
The principal quantum number is one of the four quantum numbers associated with an atom.
It is denoted by a number n=1,2,3,4 etc
It tells both size (directly) and energy (indirectly) of an orbital.
When n=1 means it is the closest to the nucleus and is the smallest orbital and with increase in principal quantum number, it depicts that size of the orbital is increasing.
It tells the energy of the orbital as well as smaller number means less distance from nucleus and having less energy. Since electrons requires to absorb energy to jump into higher orbitals making n=2,3,4 etc. Thus electrons in the orbitals with higher n number indicates higher energy orbitals.
Answer:
The speed of light is that medium is 281907786.2 m/s.
Explanation:
since the critical angle is Фc = 430, we know that the refractive index is given by:
n = 1/sin(Фc)
= 1/sin(430)
= 1.06
then if n is the refractive index of the medium and c is the speed of light, then the speed of light in the medium is given by:
v = c/n
= (3×10^8)/(1.06)
= 281907786.2 m/s
Therefore, the speed of light is that medium is 281907786.2 m/s.
Answer:

Explanation:
Density can be found by dividing the mass by the volume.

The mass of the quartz is 30 grams and the volume is 6 cubic centimeters.

Substitute the values into the formula.

Divide.

The density of this piece of quartz is 5 grams per cubic centimeter.
Answer:
15 meters
Explanation:
The inicial energy of the ball is just potencial energy, and its value is:
E = m * g * h = m * g * 20,
where m is the ball mass, and g is the value of gravity.
In the moment that the ball strickes the ground, all potencial energy transformed into kinetic energy, and 25% of this energy is lost, so the total energy at this moment will be:
E' = 0.75 * E = 0.75 * m * g * 20 = 15*m*g
This kinetic energy will make the ball goes up again, and at the maximum height, all kinetic energy is transformed back into potencial energy.
So, as the mass and the gravity are constants, we can calculate the height the ball will reach:
E' = m*g*h = 15*m*g -> h = 15 meters