Displacement = 31 - 16 = +15 m
Answer:
Below!
Explanation:
The citric acid in the lemon acts as an electrolyte, a solution that conducts electricity. The zinc nail sheds electrons as electrically charged ions into the acid (a process called “Oxidation” because the material loses electrons). ... The average lemon output is . 9 volts at .
As long as all the waves stay in the same medium, the intensity of
any waves ... electromagnetic or mechanical ... decrease in proportion
to the square of the distance.
If the distance increases to 3 x the original distance, then the intensity
changes to 1/3² or 1/9 of the original intensity.
I suppose choice-'d' is the correct one, but I have to tell you that
the phrase "nine times as low" is mathematically meaningless,
and it really grinds my gears.
Using the average velocity formula which is total distance divided by total time. If the distance is given in km convert to m then divide by 1000 to get m and if time is given in minutes then divide by 60 to get seconds. And after converting, divide to get your final answer in m/s. Hope that helped!