Answer:
A. a rigorously tested explanation
Explanation:
- B. and D. are out - theories are not opinionated, they are factual
- C. is out - not all theories are mathematical
- A. is the best choice
Answer:
The runner's acceleration was 
Explanation:
<u>Constant Acceleration Motion</u>
It's a type of motion in which the velocity of an object changes by an equal amount in every equal period of time.
Being a the constant acceleration, vo the initial speed, vf the final speed, and t the time, the following relation applies:

Solving for a:

The runner speeds up from vo=5 m/s to vf=9 m/s in t=4 seconds, thus:


The runner's acceleration was 
Aristotle created and it’s credited as the creator.
Answer: It indicates the speed of a object. The steeper the line the greater the speed of the object.