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
the magnitude of charge=q=8.76 x 10⁻⁵C
Explanation:
the magnetic force Fm is given by
Fm= q V B sinθ
q= charge
v= velocity= 2.5 x 10⁴ m/s
B= magnetic field strength= 8.1 x 10⁻²T
Fm= magnetic force= 7.5 x 10⁻² N
θ=25°
so 7.5 x 10⁻² =q (2.5 x 10⁴ ) (8.1 x 10⁻²) sin25
q=8.76 x 10⁻⁵C
<h2>QUESTION:- </h2>
➜what is kepler's law??

Kepler gave the three laws or theorems of motion of the orbitals bodies

This law state that the celestial bodies revolves around the stars in elliptical orbit and star as a single focus.
Example :- Earth revolves around the Sun as assuming it as single focus
This also shows that earth revolves around the sun in elliptical orbit.

Area covered by the planet is equal in equal duration of time irrespective of the position of the planet.
It also states that Angular momentum is constant
As Angular momentum is constant it means areal velocity is also constant.

where:-
A is the area.
T is the time.
L is the angular momentum.
M is the mass of the body.

square of the time of the revolution is directly proportional to the cube of the distance between the planet and star in Astronomical unit.

where:-
T = time of revolution
a is the distance between the planet and star.

Answer: Charge = -2.4x10^-9 Coulombs
Explanation:
The charge of one electron is e = -1.6x10^-19 C
Then, the charge of 1.5 x 10^10 electrons is equal to 1.5 x 10^10 times the charge of one electron:
Here i will use the relation (a^b)*(a^c) = a^(b + c)
Charge = ( 1.5 x 10^10)*( -1.6x10^-19 C) = -2.4x10^(10 - 19) C
Charge = -2.4x10^-9 C
This is what wiki says hope it helps
A displacement is a vector whose length is the shortest distance from the initial to the final position of a point P.[1] It quantifies both the distance and direction of an imaginary motion along a straight line from the initial position to the final position of the point.
A displacement may be also described as a 'relative position': the final position of a point (Sf) relative to its initial position (Si), and a displacement vector can be mathematically defined as the difference between the final and initial position vectors: