Sorting high mem processes

Hi

I'm new to this forum as well as relatively new to PS scripting (though I've used it for networking purposes). I'm trying to make a script that will select processes with a higher value of paged memory than, say, 750MB, and stop them. I've tried makig it with an array and foreach loop, but when I make a variable

$PS= Get-Object | Where {$_.PM -ge 750000000}

It works but does not behave like an array, so I cannot use foreach or length property. I would appreciate any help on this topic

Thanks in advance