Answer:
Atomic Theory. Learn vocabulary, terms, and more with flashcards, games, and other study tools. ... thinking about the smallest particles of matter without experimenting. Click again to see ... What new characteristic did John Dalton add to the model of the atom? An atom can join with other kinds of atoms.
a) For the motion of car with uniform velocity we have ,
, where s is the displacement, u is the initial velocity, t is the time taken a is the acceleration.
In this case s = 520 m, t = 223 seconds, a =0 
Substituting

The constant velocity of car a = 2.33 m/s
b) We have 
s = 520 m, t = 223 seconds, u =0 m/s
Substituting

Now we have v = u+at, where v is the final velocity
Substituting
v = 0+0.0209*223 = 4.66 m/s
So final velocity of car b = 4.66 m/s
c) Acceleration = 0.0209 
Answer:
The acceleration is constant and positive
Explanation:
The straight line indicates that the acceleration is constant, while the positive slope indicates that the line is positive.
Answer:
Gwen’s assumption of asteroid hit as long term change is incorrect. Asteroid hit is not a long term change, instead, it is a short term change.
Explanation:
Examples of short term changes are drought, flood, volcanic eruption, etc. A short term change occurs quickly and can immediately affect organisms but it doesn’t become a reason for species extinction. The effects of a short term change don’t prevail over a long span of time.
Examples of long term changes are ice age, global warming, deforestation, etc. Unlike a short term change, it takes time but the consequences are far-reaching. It can lead to species extinction.
In this question, asteroid hit is a quick and unexpected hazard, unlike the slow long term environmental changes.