Newton's laws
The key idea
Newton’s laws connect forces to changes in motion. In an inertial frame, the net force determines acceleration through the relation F = ma.
Why it matters
The laws are powerful because they turn a force diagram into predictions about motion; the difficult part is often identifying the system and forces correctly.
A picture to remember
The laws are powerful because they turn a force diagram into predictions about motion; the difficult part is often identifying the system and forces correctly.