Answer:
a) 46.5º b) 64.4º
Explanation:
To solve this problem we will use the laws of geometric optics
a) For this part we will use the law of reflection that states that the reflected and incident angle are equal
θ = 43.5º
This angle measured from the surface is
θ_r = 90 -43.5
θ_s = 46.5º
b) In this part the law of refraction must be used
n₁ sin θ₁ = n₂. Sin θ₂
sin θ₂ = n₁ / n₂ sin θ₁
The index of air refraction is n₁ = 1
The angle is this equation is measured between the vertical line called normal, if the angles are measured with respect to the surface
θ_s = 90 - θ
θ_s = 90- 43.5
θ_s = 46.5º
sin θ₂ = 1 / 1.68 sin 46.5
sin θ₂ = 0.4318
θ₂ = 25.6º
The angle with respect to the surface is
θ₂_s = 90 - 25.6
θ₂_s = 64.4º
measured in the fourth quadrant
Explanation:
Charges,

The distance between charges, r = 10 cm = 0.1 m
We need to find the magnitude and direction of the electric force. It is given by :

So, the required force between charges is 36 N and it is towards positive charge i.e. +8 μC.
Elements with atomic numbers from 58 through 71 are part of the
<span>
lanthanide</span> series <span />
Explanation:
Iron transition metal
Potassium Alkaline metal
Strontium Alkaline earth metal
Platinum transition metal
The periodic table arranges elements based on their atomic numbers into periods and groups. Atomic number is the number of protons an atom contains.
On the periodic table:
Group IA is called Alkaline metal
Group IIA is the Alkaline earth metals
Group IIIA Boron family elements
Group VIIA Halogens
Group O Noble gases or inert gases.
Group IIIB to IIB Transition elements.
Running a check of the given elements on the periodic table will confirm answer.
Learn more:
Periodic table brainly.com/question/8543126
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