I'm not sure about the rest but for question 2:
A theory is an attempt to come up with a big picture of all we know so far. It also drives future research as people do experiments to see if what the theory predicts actually happens. When experiments don’t support the theory, you have to change the theory and try again. That’s how science works. We come up with a “best guess” (theory), and then do research to test it’s accuracy. As we discover contradictions, we adjust the theory to take those into account, and then start testing the validity of the new theory.
Answer:
Therefore the escape velocity from Mar's gravity is
m/s.
Explanation:
Escape velocity: Escape velocity is a the minimum velocity that a object needs to escape from the gravitational field of massive body.

Escape velocity
G=Universal gravitational constant = 6.673×10⁻¹¹N m²/Kg²
M= mass of Mars = 6.42×10²³ kg
R = Radius of the Mars = 3.40×10³m
The escape velocity does not depend on the velocity of a object.

m/s
Therefore the escape velocity from Mar's gravity is
m/s.
dollar bills if so def. not me but grades 4
Answer:

Explanation:
Speed = Distance / Time
So, to find distance, we actually divide distance by rime.