It takes 86 joules of energy to raise a box 2 meters using the pulley setup shown above.

Without the pulley, the box can be raised 2 meters using only 82 joules of energy. What could explain this 4-joule difference?

A.
When raising the box using the pulley, 4 joules of mechanical energy are broken down into protons, neutrons, and electrons.
B.
When raising the box using the pulley, 4 joules of mechanical energy are transformed into water.
C.
When raising the box using the pulley, 4 joules of mechanical energy are converted into heat energy due to friction.
D.
When raising the box using the pulley, 4 joules of mechanical energy are destroyed.

The answer is C, when raising the box using the pulley, 4 joules of mechanical energy are converted into heat energy due to friction. :)

Explanation:

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.