Dear Mark,

    I have simulated the case with new drag force ratios:
k=100, speed = 0.19 cm/s
k=1000, speed = 0.052 cm/s


    Well, the particle cannot be stopped. Even bitumen has some limited viscosity and the particle will be moving through it:
https://en.wikipedia.org/wiki/Pitch_drop_experiment

    
    I had to reduce integration time step to keep the process convergence stable. So the particle traveled only a small distance so far (13000 steps * 10 microseconds =  0.13 sec). But I can keep on calculating the trajectory if needed.

     In fact after initial oscillations have subdued the speed changes very gradually. Probably we should spend some time and modify this simple integration algorithm. For once we can invent variable time step so that we can integrate  with larger time-steps if the speed variation is low and get the results faster.
    
    I attach only small portions of calculated results. The full data will be copied to
stuff.quickfield.com/MarkArokiaraj/
    Time spent 1 hour.


Best regards,
        Alex


On 21.03.2019 5:48, Mark Arokiaraj wrote:
> Dear Alex,
>
>            We will also calculate further for 100 times and 1000 times the drag force. We will see the displacement and velocity.
>
> with regards,
> Mark