Well, that's simple:

$ping = New-Object System.Net.NetworkInformation.Ping;
[bool]($ping.Send($computer, $pingTimeout).Status -ne 'Success');

It gets more interesting when we need to verify that $computer is actually valid.  We can use [System.Net.DNS]::GetHostAddresses(), but that emits an error if the host doesn't exist, which can be disconcerting if we're trying to write something that looks pretty.  In this case, we'll use trap {} to suppress the error message and get on with our lives:

& {trap { continue; } $script:hostEntry = [System.Net.Dns]::GetHostEntry($computer); }
[bool]$script:hostEntry   ; 

Put it all together, and we get:

 function Ping-Computer {
    param (
        [string]$computer,
        [int]$pingTimeout = 1000 # in milliseconds
    );
   
    if (!$computer) {
        Write-Warning "-computer not specified, required.";
        return $false;
    }
   
    $script:hostEntry = $null;
    & { trap { continue; } $script:hostEntry = [System.Net.Dns]::GetHostEntry($computer); }

    if (!$script:hostEntry) {
        Write-Warning "$computer is not known.";
        return $false;
    }
   
    $script:pingStatus = $null;
    & { trap { continue; } $script:pingStatus = (New-Object System.Net.NetworkInformation.Ping).Send($computer, $pingTimeout).Status; }

    if ($script:pingStatus -ne 'Success') {
        Write-Warning "$computer is not pingable.";
        return $false;
    }

    return $true;
}