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).
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Answer:
Local action is removed by amalgamating zinc rod.
Explanation:
This prevents chemical reaction to occur because impurities in the zinc cannot get into contact with an electrolyte.
Answer:
therefore critical angle c= 69.79°
Explanation:
Canola oil is less dense than water, so it floats over water.
Given 
which is higher than that of water
refractive index of water 
to calculate critical angle of light going from the oil into water
we know that

now putting values we get

c= 
c=69.79°
therefore critical angle c= 69.79°
<u>Answer</u>
D. Base units
<u>Explanation</u>
Basic units are also called fundamental units. They are the standard units agreed internationally for measurements. Most of these measurements are taken from the ground and they are used to derive other units. They are seven in number. There are:
The metre (m)
The kilogram (kg)
The second (s)
The ampere (A)
The kelvin (K)
The candela (cd)
The mole (mol)