Please note this script may take a good few seconds to return results:

Import-Module WebAdministration
$processes = Get-WmiObject Win32_PerfFormattedData_PerfProc_Process | Where-Object {$_.Name -like "w3wp*"}
$apppools = & "$env:systemroot\system32\inetsrv\appcmd" list wp
$coreCount = (Get-WmiObject Win32_ComputerSystem).NumberOfLogicalProcessors

foreach ($proc in $processes) {
    $processId = $proc.IDProcess
    $apppool = ($apppools | Where-Object {$_ -match "WP `"$processId`""}) -replace '.*applicationPool:([^\)]+)\).*','$1'
    
    [PSCustomObject]@{
        ProcessID = $processId
        AppPoolName = $apppool
        "CPU(%)" = [math]::Round($proc.PercentProcessorTime / $coreCount, 2)
        "Memory(MB)" = [math]::Round($proc.WorkingSetPrivate/1MB,2)
    }
}