Linear drag pushes back against motion with a force equal to the drag coefficient times speed, so a faster object feels more resistance. The drag coefficient 3 N*s/m times speed 4 m/s gives an opposing drag force of 12 N exactly for the stated toy motion ledger; real cellular motion has variable drag, nonuniform media, stochastic forcing, imaging limits, and biological variability.
A linear drag coefficient maps speed to an opposing force. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Bind speed and drag coefficient
The drag coefficient is 3 N*s/m and the speed is 4 m/s.