What are coriolis forces? Measured in the (non-inertial) frame of the earth, some motions appear to require fictitious forces, including centrifugal force and coriolis force.
Newton's laws: more background
Galileo's idealisation. The 'natural state' of motion. How big are the units of force? Some common approximations and simplifications.
How do sailboats make their way against the wind? How can they sometimes sail faster than the wind? This page gives explanations in terms of Newton's laws and vector addition.
Car Physics: drag, acceleration and kinematics for cars