And to add to that, ezine's minimal requirement per article is 250 words per submission. My knowledge within my niche is superb, so I can easily write 1k-2k words per hour if not more. Split that into 5-10 articles and walla. That's without doing research also. So as long as your knowledge is on par with whatever your specialty is, 10+ articles is highly achievable.
It's possible but not plausible. Are you running a marathon? Is this a race? Then yeah, if you say to me "write me 20 1k word articles in one day and i'll give you 100$" I can do it, perfect English and all. But very few people will dedicate the time and actually make the articles worth reading. It's possible, but people don't usually do it. And unless you're just writing randomly about your niche without much thought into the article or research or to include any valuable information then it's just not going to happen. It does not take 48 hours, on average it takes 5-6 days. Maybe you have some platinum status allowing your reviews to be 48 hours or less, but most people do not. With the amount of people also writing articles, it seems like it won't get many views either. But as the other guy said "every penny counts" then that's true I suppose.
I would suggest you to submit 2 articles a week... I say this because most of the article directories are human edited... your articles are reviewed before being approved... therefore, if you submit more articles there are more chances for rejection of your articles
I recently submitted an article about Abs and got over 218 views and 54 url clicks within one day. My best record yet within 24 hours time. Just goes to show if you hit your keywords right and put enough effort into your articles, the possibilities are limitless.