Answer:
Because of the way light bounces off of objects.
The total moment of inertia about an axis is :
for a ring of mass m and radius straight r attached to a thin rod.
<h3>
Determine the Total moment of Inertia about an axis </h3>
<u>Given data:</u>
mass of ring --> m
radius of ring --> r
mass of rod --> M
Length of rod ---> L ( 2 * radius )
Total Moment of Inertia about an axis = Irod + Iring
where : Irod = moment of inertia of rod, Iring = moment of inertia of ring
Irod = ML² / 3
Iring = 2mr² / 5
moment of inertia around an axis by Iring = I
where ; I = 2mr² / 5 + ML² according to parallel axis theorem
Hence the Total moment of Inertia about an axis is :
Itotal = 2mr²/5 + ML² + ML² / 3
= 
Learn more about Moment of inertia : brainly.com/question/6956628
To solve this problem we will use the three requested concepts: Wavelength, frequency and period.
The wavelength is the distance between each crest, therefore it is already given and is 0.8m
<em>The correct answer is C.</em>
The frequency can be described as a relationship between wave speed and wavelength therefore



<em>The correct answer is B.</em>
The period is the inverse of the frequency therefore



<em>The correct answer is B.</em>
There are 4 ways in which electrons are emitted from the conductor.
i. Thermionic emission
ii. Electric field electron emission
iii. Photoelectric emission
iv. Secondary emission
In thermionic emission large amount of external energy in the form of heat is supplied to release free electrons from the metal.
In electric field electron emission, electrons are emitted from the metal surface when the metals are placed in a very strong electric field.
During photoelectric emission, light is absorbed by the metals and this provides energy to the valence electrons which break their bond with the parent atom and which are then released from the atom.
Valence electrons do have some kinetic energy, but they don't have enough energy to escape from the atom. During secondary emission, a high-speed electron is bombarded with an atom, which provides the energy for the valence electrons to break their bonds with their parent atom which are then released from the atom.