Could 40 mg. of prilosec daily for 4-6 weeks be enough to cure an ulcer?

Yes: But make sure to follow up with your doctor before stopping the medication.

Yes, but...: Most ulcers of the stomach and duodenum are due to infection with a bacteria, h. Pylori. Some due to meds:eg aspirin, Ibuprofen other nsaids; uncommonly due to other including lymphoma, crohn's, tb, gist (stromal tumors), tumors of neuroendocrine origin (carcinoids), poor blood flow, other stomach ulcers need follow up to healing (some are really ulcerated cancers). If h. Pylori, rx incl antibiot.

Depends on cause : You not only need to take the antacid, but you also need to avoid the precipitant that caused the ulcer (meds, alcohol, tobacco). It's a balancing act and just taking an antacid may not be enough.

Yes: Six weeks of Prilosec will cure most ulcers. But there are a few questions that go with this. First, how do you know this was "an ulcer" and not something else. Second, if it is an ulcer, the two most common causes are h. Pylori infection and non steroid use like aspirin.