Get CPU and RAM usage for specific process and output to log file

Hi,

I want to monitor CPU and RAM usage for 1 specific application and extract it to a txt file. 

Using get-process gives me all the different values but I just want CPU value. Below is my script, when I tried $process.CPU, it does not give me the CPU usage and could someone shows me how to extract these information to a txt file?

Thanks

$Processes = get-process chrome | Group-Object -Property ProcessName

foreach($Process in $Processes)
{
    $Obj = New-Object psobject
    $Obj | Add-Member -MemberType NoteProperty -Name Name -Value $Process.Name
    $Obj | Add-Member -MemberType NoteProperty -Name Mem -Value ($Process.Group|Measure-Object WorkingSet -Sum).Sum
    $Obj | Add-Member -MemberType NoteProperty -Name CPU -Value $Process.CPU  
    $Obj    
}