A surgical system for applying an energy applicator to a target tissue and methods operating the same are disclosed. The energy applicator extends from a surgical instrument. The surgical system comprises a sensor to measure external forces and torques placed on the surgical instrument. A surgical manipulator is configured to move the energy applicator in a manual mode in response to the external forces and torques. At least one controller is configured to: model the surgical instrument and the energy applicator as a virtual rigid body having a virtual mass； calculate, using impulse modeling, constraining forces and torques to be applied to the virtual rigid body； determine total forces and torques based on the external forces and torques and the constraining forces and torques； and advance the energy applicator in the manual mode based on the total forces and torques.
