The answer you are looking for is Gneiss my dude.
No. The companion is wrong.
You are shivering because, since it's cold outside, your body is becoming incapable of maintaining the the same temperature outside ad well as inside.
So, in order to compensate, your body uses mechanism of shivering in order to produce more heat by constricting the blood flow in vessels.
Therefore, you shiver from cold.
Gravitational potential energy is energy an object possesses because of its position in a gravitational field. The most common use of gravitational potential energy is for an object near the surface of the Earth where the gravitational acceleration can be assumed to be constant at about 9.8 m/s2.
Power is rate of transfer of energy.
You use Beers Law.
A = εmCl
Where A=absorbance, εm = molar extinction coefficient, C = concentration, l=path length of 1 cm)