Physics 01
Block on an Inclined Plane With Friction: How to Solve It
How to solve a block on an inclined plane with friction: the free-body diagram, weight components, normal force, whether it slides, and worked examples.
forces
Physics 02
Why Do You Feel Pushed Outward on a Bend?
Nothing pushes you outward on a bend: the car turns and you go straight. Centrifugal vs centripetal force, with numbers for cars, spin cycles and orbits.
Physics 03
Why Don't You Feel the Gravity of the Person Next to You?
Two people 1 m apart attract each other with 3.3 × 10⁻⁷ N. Here is the calculation, why Earth wins by a factor of two billion, and when the pull matters.