Their average velocity is 0.98 m/s east.
Explanation:
The average velocity of an object is defined as the ratio between the displacement and the time taken:

The displacement is a vector connecting the initial point to the final point of motion: so, being displacement a vector, velocity is a vector as well, having the same direction of displacement.
Here, Heather and Matt walk 2.0 km eastward, so their displacement is
d = 2.0 km = 2000 m (east)
While the time they took is

Therefore, their average velocity is

And the direction is the same as the displacement (east).
Learn more about average velocity:
brainly.com/question/5248528
#LearnwithBrainly
Modelling the structure of the atom is important because modeling replaces the real system with something similar but easier to examine. Option B
<h3>What is modeling?</h3>
A model is a representation of reality. We know that a model could help us to recreate reality in a manner that we could be able to relate fully with it. A model could be used also a means of explanation.
The atomic models that we have usually help us to understand more abut the atom. Therefore, modelling the structure of the atom is important because modeling replaces the real system with something similar but easier to examine. Option B
Learn more about modelling the atom:brainly.com/question/1596638
#SPJ1
A transformer is used to increase or decrease a voltage. BUT ... it has to be an AC voltage, or the transformer doesn't work.
C explanation: There are many examples of fossils found on separate continents and nowhere else, suggesting the continents were once joined. If Continental Drift had not occurred, the alternative explanations would be: They swam to the other continent/s in breeding pairs to establish a second population. ...