True.
A contact force is a force between two objects that are physically in contact with each other: an example of a contact force is the normal reaction of a table supporting a book.
A non-contact force is a force between two objects that are not physically in contact with each other: an example of non-contact force is the gravitational attraction between the Earth and the Moon.
Answer:
- The energy that must be added to the electron to move it to the third excited state is -1.153 eV
- The energy that must be added to the electron to move it to the fourth excited state is -1.181 eV
Explanation:
Given;
Energy of electron in ground state (n = 1 ) = 1.23 eV
E₁ = 1.23 eV
Eₙ = E₁ /n²
where;
E₁ is the energy of the electron in ground state
n is the energy level,
For third excited state, n = 4
E₄ = E₁ /4²
E₄ = (1.23 eV) / 16
E₄ = 0.077 eV
Change in energy level, = E₄ - E₁ = 0.077 eV - 1.23 eV = -1.153 eV
The energy that must be added to the electron to move it to the third excited state is -1.153 eV
For fourth excited state, n = 5
E₅ = E₁ /5²
E₄ = (1.23 eV) / 25
E₄ = 0.049 eV
Change in energy level, = E₅ - E₁ = 0.049 eV - 1.23 eV = -1.181 eV
The energy that must be added to the electron to move it to the fourth excited state is -1.181 eV
The angle of reflection is "60°".
Here we apply the law of the concept of reflection then we get the final answer easily.
The angle of incident = angle of reflection
Then, the Angle of the incident =60°
What is reflection?
- Reflection is the phenomenon of light rays returning to the source after striking an obstruction.
- It resembles the way a ball bounces when we toss it on a hard surface.
- Some of the light rays that strike an item are reflected, some of them travel through it, and the remainder are absorbed by the object.
- The given values are:Light from a monochromatic source,= 560 nm
- The angle of incidence,= 60°
- The surface of fused quartz (n),= 1.56
- When a light ray does exist on a flat surface, the law or idea of reflection should apply since it includes both the reflected and "normal" light rays at the mirror surface.
- According to the above law,Angle of incident = angle of reflection
- Then, Angle of incident =60°.
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Answer:
Ice is the solid state of water, a normally liquid substance that freezes to the solid state at temperatures of 0 °C (32 °F) or lower and expands to the gaseous state at temperatures of 100 °C (212 °F) or higher.
Explanation:
The deflection angle is 37.29º if the prism was made of polystyrene plastic.
What is a laser beam?
Laser beam is a light beam propagating dominantly in one direction.
It is a beam of radiation produced from a laser.
Here given that,
refraction index of glass, n1= 1.52
refraction index of polystyrene plastic, n2 = 1.59
deflection angle, B = 22.6º
For the second surface,
B = 45º - 22.6º
B = 22.40º
Now from the formula of Snell's law:
n1 sinФ = n2 sin B
sin B / sinФ = n1 / n2
sinФ = (sin 22.40º) * ( 1/ 1.59)
Ф = 37.29º
Hence,
The deflection angle is 37.29º if the prism was made of polystyrene plastic.
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