Help me understand these following code snippet from Chaos Vehicle plugins?

Development Programming & Scripting
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1

Hi guys,
I’m trying to understand the logic implemented in Chaos Vehicle plugin? I need your help with following points:

1/ Torque conversion

If I’m not wrong then brake torque unit is Nm, then convert to Ncm required multiply by 100. But as shown in the code, the brake torque is multiplied by 10000

UE_5.4\Engine\Plugins\Experimental\ChaosVehiclesPlugin\Source\ChaosVehicles\Private\ChaosWheeledVehicleMovementComponent.cpp

        if (PWheel.BrakeEnabled)
        {
            float BrakeForce = PWheel.MaxBrakeTorque * ModifiedInputs.BrakeInput;
            PWheel.SetBrakeTorque(TorqueMToCm(BrakeForce + EngineBrakingForce), FMath::Abs(EngineBrakingForce) > FMath::Abs(BrakeForce));
        }
        else
        {
            PWheel.SetBrakeTorque(TorqueMToCm(EngineBraking), true);
        }

UE_5.4\Engine\Source\Runtime\Experimental\ChaosVehicles\ChaosVehiclesCore\Public\VehicleUtility.h

    FORCEINLINE float TorqueMToCm(float TorqueIn)
    {
        return TorqueIn * 10000.0f;
    }

2/ Force required to stop a wheel

What is the meaning of K? is it some kind of friction coefficient, why is the value set to 0.4?

UE_5.4\Engine\Source\Runtime\Experimental\ChaosVehicles\ChaosVehiclesCore\Private\WheelSystem.cpp

    void FSimpleWheelSim::Simulate(float DeltaTime)
    {
        float K = 0.4f;
        float TractionControlAndABSScaling = 0.98f;
 // how close to perfection is the system working

                if (Braking)
                {
                    // whether the velocity is +ve or -ve when we brake we are slowing the vehicle down
                    // so force is opposing current direction of travel.
                    float ForceRequiredToBringToStop = MassPerWheel * K * (LocalWheelVelocity.X) / DeltaTime;
                    FinalLongitudinalForce = AppliedLinearBrakeForce;