You need to provide much more information. Half dollars have been made for over two centuries at about a half-dozen mints so at a bare minimum you need to identify its date, condition, and mint mark.
If it's a current (1971-present) Kennedy half, it's made of copper-nickel, not silver, and is worth exactly 50 cents unless it's a proof coin in the original package.
If it's dated 1965 to 1969 it's made of 40% silver and is worth about $2.75 to $3.00 as of 02/2010.
If it's older than that it's made of 90% silver and its value is very dependent on its date and mint mark. If your coin is dated 1964 or earlier please post a new and more specific question. This is especially important for the Ben Franklin coins 1948-1963 and the earlier Liberty Walking halves.
Anywhere from 50 cents up. Almost any Kennedy half made since 1971 that has been circulated even a little bit is only worth face value. Most of them are available in uncirculated condition for less than $2. Anything older is worth at least the value of the silver it contains. Coins in excellent condition may be worth more than their silver value.
50$
Value is for the silver about $2.50
The US didn't strike any half dollars in 1804.
50 cents.
50 cents.
50$
A US half dollar with a date of 1979 is a Kennedy half dollar not a liberty half dollar. The coin has no silver and is only face value.
It has a metal value of about $10.
Value is for the silver about $2.50
About $4-5
50 cents.
a half dollar
The US didn't strike any half dollars in 1804.
A U.S. half dollar dated 1953 or 1952 is a Franklin half dollar. If it shows any wear, the value is only for the silver, about $10.00. The coins are very common.
A US half dollar with a date of 1983 is a Kennedy half dollar not a liberty half dollar.The coin has no silver and most are only face value.
The value of a US 1964 half dollar in circulated condition is around $10. in uncirculated condition they are worth around $16.
50 cents.