I am trying to develop a Multisim simulation to demonstrate the effects of varying load torque, friction and inertia on a DC motor. Despite numerous attempts, I cannot seem to figure out how to do this. I would like the simulation to demonstrate the rise/fall time of the motor speed in response to variations in load characteristics, and also to plot motor speed vs. applied voltage and varying load torque. I would then like to use the motor in closed-loop simulations for speed control and position control. Any tidbits of advice will be greatly appreciated!