The role energy would have played in forming the black sand on the beach
will be through the erosion and movement of the particles.
Black sand from the beach are formed as a result of the erosion of volcanic
material , dark-colored rocks and minerals. Erosion helps to carry these
particles to the beach thereby making the color of the sand to become dark.
The wave energy present at the beach erodes and moves the materials to
different parts of the beach.
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Answer: The answers are the first and third options.
the force between the electron and the proton.
a) Use F = k * q1 * q2 / d²
where k = 8.99e9 N·m²/C²
and q1 = -1.602e-19 C (electron)
and q2 = 1.602e-19 C (proton)
and d = distance between point charges = 0.53e-10 m
The negative result indicates "attraction".
the radial acceleration of the electron.
b) Here, just use F = ma
where F was found above, and
m = mass of electron = 9.11e-31kg, if memory serves
a = radial acceleration
the speed of the electron.
c) Now use a = v² / r
where a was found above
and r was given
<span> the period of the circular motion.</span>
d) period T = 2π / ω = 2πr / v
where v was found above
and r was given
2Ca + 2H2O —-> Ca(OH)2 + H2