Forces & Dynamics
Explain changes in motion by identifying interactions, representing them as force vectors, combining those vectors, and connecting the net force to acceleration.
A force is not something an object stores. It is an interaction happening between systems.
Dynamics becomes much more intuitive when the interaction comes first. Identify what is interacting, name the force model, isolate the system, combine its vectors, and only then ask how the motion responds.
Build the model from interaction to motion.
Live lessons open normally. Planned stations preserve the conceptual route without pretending unfinished pages are ready.
Forces belong to interactions
If you cannot name what other object or field is interacting with the system, the force description is incomplete.
Vectors belong to one chosen system
A free-body diagram includes forces acting on the selected system, not every force everywhere in the scene.
Net force changes velocity
A nonzero net force means acceleration. It does not mean the object must already be moving in the force direction.