Answer:
B, A, A, B
Explanation:
Just trust me on this one.
Explanation:
(a)
The photoelectric effect is the phenomenon in which the light of the particular frequency incidents on the material. Then the emission of the electrons from the surface of the material occurs.
This phenomenon could not be explained by Newtonian physics.
In Newtonian physics, the energy is not discrete. In quantum mechanics, the energy is discrete. This is the main why the photoelectric effect could not be explained by Newtonian physics.
(b)
Light consists of photons. The photon is a packet of energy. It is also called quanta. The energies of the photons are quantized.
When a photon strikes on the surface of metal then the energy of photon is absorbed by an electron in the metal so that it may eject from the surface. This phenomenon is called the photoelectric effect.
(c)
In quantum mechanics, wave-particle duality concept is used to explain the wave-particle nature of the light. Light behaves as particle as well as wave. It shows both nature. The photoelectric phenomenon shows the particle nature of the light. It acts as a particle when it hits the surface of the metal.
In line spectra, the electron is excited to an energy level. In this case energy is transferred from photon to electron. There is a collision between photon and electron. The change in momentum will occur. It shows the particle nature of the light.
Answer:
The work done by Ramas is 3920 N.
Explanation:
Given;
mass of the load lifted by Ramas, m = 20 kg
height through which the load is lifted, h = 20 m
The work done by Ramas is equal to gravitational potential due to the height in which the load is lifted.
W = PE = mgh
where;
g is acceleration due to gravity = 9.8 m/s²
W = 20 x 9.8 x 20
W = 3920 N.
Therefore, the work done by Ramas is 3920 N.
