The Definition of Work is given by:
Entering the unknowns, we have:

If you notice any mistake in my english, please let me know, because i am not native.
An electric current is said to exist when there is a net flow of electric charge through a region. In electric circuits this charge is often carried by electrons moving through a wire. It can also be carried by ions in an electrolyte, or by both ions and electrons such as in an ionized gas (plasma).
Answer:
The solution is shown in the picture attached below
Explanation:
Answer:
Explanation:
Basically, the point on the axis of a lens or mirror to which parallel rays of light converge or from which they appear to diverge after refraction or reflection.
Not sure if this is what your looking for. Hope this helps!