A student claims that the free-body diagram of a lamp hanging at rest from the ceiling by a single light cord contains three forces: its weight downward, the tension upward, and an additional "support force" from the ceiling upward.
a. (i) Draw a correct free-body diagram of the lamp.
b. (ii) Explain clearly why the extra "support force" shown by the student is incorrect.
c. (iii) The student further suggests adding a force exerted by the air on the lamp. Explain whether this force should be included in the free-body diagram and justify your answer.