Use the drop-down menus to complete each statement.
2 answers:
Answer:
The amount of matter in an object is its mass
An action that has the ability to change an object's state of motion is a force
The rate at which velocity changes over time is acceleration
Explanation:
- Mass is a scalar quantity that gives a measure of the amount of matter contained in an object/substance. The SI unit of the mass is the kilogram (kg). Mass is an intrinsec property of an object, that means that it does not change when the object is moved in another location.
- A force is a vector quantity, that indicates an action exerted on an object that changes the state of motion of the object. It is measured in Newtons (N). According to Newton's second law, the acceleration of an object is equal to the net force exerted on the object divided by its mass:
- Acceleration is a vector quantity, which is equal to the ratio between the change in velocity of an object and the time interval taken for that change to occur. It is measured in meters per second squared (). Mathematically, it is defined as
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1) D
2) D.) Greater than
Explanation:
1)
The phenomenon of total internal reflection occurs when a ray of light hitting the interface between two mediums is totally reflected back into the original medium, therefore no refraction into the second medium occurs.
This phenomenon occurs only if two conditions are satisfied:
- The index of refraction of the first medium is larger than the index of refraction of the 2nd medium
- The angle of incidence is greater than a certain angle called critical angle
In picture 1, we have 4 different diagrams. In the diagrams:
- The red arrow represents the incident ray
- The green arrow represents the refracted ray
- The blue arrow represents the reflected ray
Total internal reflection occurs when there is no refraction, therefore when there is no green arrow: this occurs only in figure D, so this is the correct option. (in figure C, there is a refracted ray but it is parallel to the interface: this condition occurs when the angle of incidence is exactly equal to the critical angle, however in this problem, the angle of incidence is greater than the critical angle, so the correct option is D)
2)
As we stated in problem 1), total internal reflection occurs when the angle of incidence is equal or greater than the critical angle. Therefore in this case, the angle of incidence must be
D.) Greater than
Answer:
|F| = 2.09 × 10⁻⁸ assuming that the two ions are point charges.
Explanation:
What's the charge on each ion?
The symbol here stands for fundamental charge. Each electron carries a negative fundamental charge of -e. Each proton carry a positive fundamental charge of +e.
Molecules and atoms are neutral. They contain an equal number of electrons and protons. Remove one electron from a molecule or atom, and that particle will end up with more protons (which are positive) than electrons. That particle will carry a positive charge of +e become an ion (a cation to be precise.) Remove another electron and the ion will carry a charge of +2e.
For each ion .
What's the size of the electrostatic force between the two ions?
Consider Coulomb's Law for the electrostatic force between two point charges:
,
where
is Coulomb's constant,
and
are the charge on the two point charges, and
is the separation between the two charges.
Make sure that all values are in SI units. Assume that the two ions are small enough that they act like point charges:
.
The value of is negative, meaning that the two charges will repel each other because they are both positive. The question is asking for the magnitude of this force. Thus drop the sign in front of
to obtain
, which is the magnitude of
.