How to copy files from one document library to another library using powershell

$siteURL="http://serverName:1111/"
$site=Get-SPSite $siteURL
$web=$site.RootWeb
$collFiles=$web.GetFolder("Shared Documents").Files
foreach($file in $collFiles)
{
 $file.CopyTo("Destination Library/"+$file.Name,$true)
}