History is open to ongoing and changing interpretations because changing <span>values limit interpretation.
So your answer is A.</span>
The energy that then radiates out from the surface, longwave radiation, is trapped by the same greenhouse gases, warming the air, oceans, and land. This process, appropriately dubbed “the greenhouse effect,” is how global warming occurs.
the upward force the desk pushes on the book.
from the free body diagram of the book, it is clear that on the book, there are two forces acting.
1) normal force F by the desk in Upward direction.
2) force of gravity by earth in downward direction.
The Upward normal force by the desk on the book balances the force of gravity by earth in downward direction. that is why the book remains stationary on the desk.
Answer: The electron number density (the number of electrons per unit volume) in the wire is
.
Explanation:
Given: Current = 5.0 A
Area = 
Density = 2.7
, Molar mass = 27 g
The electron density is calculated as follows.

where,
= density
M = molar mass
= Avogadro's number
Substitute the values into above formula as follows.

Thus, we can conclude that the electron number density (the number of electrons per unit volume) in the wire is
.