These two forces are called action and reaction forces and are the subject of Newton's third law of motion. Formally stated, Newton's third law is: For every action, there is an equal and opposite reaction. The statement means that in every interaction, there is a pair of forces acting on the two interacting objects.
Answer:
Explanation:
11 = y/3+7
collecting like terms
11 - 7 = y/3
4 = y/3
multiplying both sides by 3 gives us
12 = y
therefore
y = 12
Answer:

Explanation:
M = Mass of planets
R = Radius of circle
v = Velocity
= Angle
The circle is inside the triangle

The centripetal acceleration

The speed of the stars is 
Answer:
θ = 45º
Explanation:
The light that falls on the second polarized is polarized, therefore it is governed by the law of Maluz
I = I₀ cos² θ
in the problem they ask us
I = ½ I₀
let's look for the angles
½ I₀ = I₀ cos² θ
cos θ = √ ½ = 0.707
θ = cos 0.707
θ = 45º