TR3.5

Center of Mass

Houjun Liu 2021-09-27 Mon 12:00

The center of gravity is the same thing as the center of mass, except when the gravitational field you are in is not uniform.

1 Where's the center?

For triangles:

  • Perpendicular bisectors: circumcenter, equal distance
  • Angle bisectors: inter-center (inscribe a circle)
  • Medians: split the medians

2 Newton's Laws

  1. Law of Inertia: An object at rest stays a rest, unless acted upon by a force; object in motion stays in constant motion unless acted
  2. \(\vec{F_{net}} = m\vec{a}\)
  3. For a set of objects A,B, Force of A->B is equal to negative of Force of B->A

\(\vec{F_{net_{system}}} = Ma_{cm}\). The force of the system is the mass times the acceleration by the center of mass.