You should trust the primary source more.
This is because the primary source is make its conclusion from direct observation, while the secondary source is possibly making reference to another secondary source or to another primary.
The primary source should be trusted more because it is from direct observation.
Answer:
The focus of Lesson 1 is Newton's first law of motion - sometimes referred to as the law of inertia. An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
The question is incomplete. You dis not provide values for A and B. Here is the complete question
Light in the air is incident at an angle to a surface of (12.0 + A) degrees on a piece of glass with an index of refraction of (1.10 + (B/100)). What is the angle between the surface and the light ray once in the glass? Give your answer in degrees and rounded to three significant figures.
A = 12
B = 18
Answer:
18.5⁰
Explanation:
Angle of incidence i = 12.0 + A
A = 12
= 12.0 + 12
= 14
Refractive index u = 1.10 + B/100
= 1.10 + 18/100
= 1.10 + 0.18
= 1.28
We then find the angle of refraction index u
u = sine i / sin r
u = sine24/sinr
1.28 = sine 24 / sine r
1.28Sine r = sin24
1.28 sine r = 0.4067
Sine r = 0.4067/1.28
r = sine^-1(0.317)
r = 18.481
= 18.5⁰
Answer:
a) 42 m/s, positive direction (to the east), b) 42 m/s, negative direction (to the west).
Explanation:
a) Let consider that Car A is moving at positive direction. Then, the relative velocity of Car A as seen by the driver of Car B is:

42 m/s, positive direction (to the east).
b) The relative velocity of Car B as seen by the drive of Car A is:

42 m/s, negative direction (to the west).
you only see the stars once every twenty for hours so you can have daylight so because of Earth's rotation you only see the stars for a certain amount of hours
Explanation:
the Earth makes a full rotation so that's why my answer is what it is