why can you only answer so many questions a day?

to stop people abusing the system by simply answering hundreds of questions a day that are not actually answers, which would allow them to rack up the awarded 2 points you get for answering without contributing to the 'community'.

if you keep at it, answering well and getting 'best answer' for 10 points you'll increase your level and the amount of answers you can give per day - reach level 5 at 5000 points or more and you can answer unlimited questions.:

http://answers.yahoo.com/info/scoring_system.php;_...

The higher your level, the more advise/answers you can give. Yahoo puts limits on lower levels to prevent spamming - if there were no limits on lower levels, this platform would get flooded with spam! But with the installed limits, chances are high to catch those culprits before they can do much harm...

ones you move level up it gets better, after level four you can answer questions all day long.

It get's better the longer you stay.

So you get a chance to use your other account sometimes.