The primary source would be the original article published in a scientific journal. All other choices would be based on information from the original article.
Newspapers would only pick up the information from the journal itself, or from the authors. Books follow after the original article, after it has gained momentum among the research community. The public lecture at a museum would be based on work from the journal article.
Answer:

Explanation:
We can solve the problem by using the following suvat equation:

where
v is the final velocity
u is the initial velocity
a is the acceleration
s is the displacement
For the car in this problem:
u = 0 (it starts from rest)
is the final velocity
s = 10 km = 10 000 m is the displacement
Solving for a, we find:

Answer: Final speed
Explaination: because its final.
Answer:
Explanation:
distance of fan A = 18.3 m
distance of fan B = 127 m
speed of sound (s) = 343 m/s
What is the time difference between hearing the sound at the two locations?
time (T) = distance / speed
- time for sound to reach fan A = 18.3 / 343 = 0.053 s
- time it takes for sound to reach fan B = 127 / 343 = 0.370 s
- time difference = 0.370 - 0.053 = 0.317 s