Answer:
A
Explanation:
Contact force A contact force is any force that requires contact to occur. ... Contact forces are often decomposed into orthogonal components, one perpendicular to the surface (s) in contact called the normal force, and one parallel to the surface (s) in contact, called the friction force. In the Standard Model of modern physics, the four fundamental forces of nature are known to be non-contact forces.
Answer:
Population inversion, in physics, the redistribution of atomic energy levels that takes place in a system so that laser action can occur. Although absorption and emission of energy is a continuous process, the statistical distribution (population) of atoms in the various energy states is constant. ...
laser inversion is photon that can stimulate the production of other photons of exactly the same wavelength because of stimulated emission of radiation.
Explanation:
Answer:
A compound
Explanation:
2 or more elements mean its a compound
Answer:
93.125 × 10^(19)
Explanation:
We are told the asteroid has acquired a net negative charge of 149 C.
Thus;
Q = -149 C
charge on electron has a value of:
e = -1.6 × 10^(-19) C
Now, for us to determine the excess electrons on the asteroid, we will just divide the net charge in excess on the asteroid by the charge of a single electron.
Thus;
n = Q/e
n = -149/(-1.6 × 10^(-19))
n = 93.125 × 10^(19)
Thus, it has 93.125 × 10^(19) more electrons than protons
In the photoelectric effect, the energy given by the incoming photon is used partially to extract the electron from the metal (work function) and the rest is converted into kinetic energy of the electron:

where
hf is the energy of the photon, with h being the Planck constant and f the frequency of the photon

is the work function
K is the kinetic energy of the electron
When K=0, we have the minimum energy required to extract the electron from the metal, so the equation becomes

(1)
If we convert the work function of gold into Joules:

We can re-arrange eq.(1) to find the minimum energy of the photon: