That's not an actual dollar coin, but rather a silver bullion round. The coin might not have a date, but it should at least mention its weight. As of 19 February 2014, silver is worth $21.84 per troy ounce.
What is a silver dollar from 1702 worth today
A dollar.
It depends on what you're calling a "Liberty dollar". All US silver dollars minted up till 1935 had a picture of Miss Liberty on the front. These are worth at least 75% of the current price of an ounce of silver, around $20 as of early 2011, and many of them are worth a lot more. The "dollar" bullion coins minted since 1986 aren't for spending and aren't really silver dollars but are worth a bit more than the price of an ounce of silver. Circulating $1 coins minted since 1971 don't have any silver and are only worth $1. If you have a specific coin you want to evaluate, please post a new question in the form "What is the value of a (date) US silver dollar?", where (date) is of course your coin's date.
Modern Silver Eagles (1986 to date) contain One Ounce of pure silver.
What date? Post new question.
What you have is a silver buillion round. As of 28 December 2013, a one ounce round is worth $20.06.
Please post a new question that's less ambiguous. If you mean "what's the value of a silver dollar", include its date and mint mark. If you mean "what's the value of a silver certificate", include its date, the letter (if any) next to the date, and denomination. If you mean "how much is a dollar's worth of silver", Google the words SPOT PRICE SILVER and divide 1 by the price in dollars per ounce to get the number of ounces in $1.
The price of silver at the end of 30 November 2004 was $7.75 per ounce.
Check that date or denomination again. There were no silver dollars minted that year.
1922 is a very common date for silver dollars. At present, they're worth around $23 each.
It is a common date worth about $10 in silver scrap since it is 90% silver.