Grade 11 · Theory
Newton's first and second laws
Newton's laws · about 3 min
Visual overview: Newton's first and second laws1 MIN READ
2 study sections · pause after each one and recall the key ideaNewton's laws connect force to motion and are the backbone of mechanics.
Key points- First law (inertia): an object stays at rest or in uniform motion unless a resultant force acts.
- Second law: Fnet = ma — acceleration is proportional to resultant force and inversely proportional to mass.
- Fnet is the VECTOR sum of all forces on the object.
- Acceleration is always in the direction of the resultant force.
- Inertia — resistance to change in motion.
- Resultant force — the net force after adding all forces.
EXAM TIP
every Fnet = ma question starts with a free-body diagram; do not skip it even when the answer feels obvious.