First:
d = 100 m
t = 200 sec
v = 100/200 = 0.5 m/s
Displacement is zero since he returned to his start point.
t2 = d/v2 = 100/2 = 50 sec
total time = 50 + 200 + 500 = 750 sec
<span>Law of Conservation of Energy states that the total amount of energy remains constant in an isolated system and Energy can be neither created nor destroyed.
</span>
Therefore,
<span>The refrigerator</span><span> removed 272 Joules of energy from the food (making it colder) and dumped 272 J of energy outside (heat of the refrigerator).</span>
Answer:
, attractive.
Explanation:
For calculating this force we use the Coulomb Law:
Where 
is the Coulomb's constant, 
and 
the values of each charge and r the distance between them.
Since the Coulomb's constant as I wrote it is in S.I. we have to write all the magnitudes in that system of units, and substitute:
This force is attractive since both charges are of opposite sign.
