Forces

What is a force?

  • Forces are a push or pull

  • always an interaction between two objects (cannot be a singular object)

  • impossible for one object to put a force on another object without it being reciprocated

  • they do not need to be in contact (magnet, gravity)

What causes a force?

  • 4 forces

    • gravity

      • acts on mass

    • electromagnetic

      • acts on things that have a charge, everything that isn’t by gravity is electromagnetic

        • there are named macro electromagnetic forces falls under this divison

    • 2 are microscopic

What do forces cause?

  • some kind of motion → speed or acceleration

    • forces causes root acceleration (unbalanced)

      • unbalanced forces are also known as net forces → difference of input/forces acted

      • acceleration needs to have unbalanced forces, feels different

What is mass?

  • a measurement of the amount of matter an object contains → kg

    • mass is always constant

What is weight?

  • the force of gravity acting on an object/mass = weight

What does it mean to be a LAW of physics?

  • zero exceptions to it


Newton is a kgm/s²


action reaction must go together


if something has mass, it cannot be same tension throughout

  • if there is no mass, tension can be assumed uniform throughout rope




the normal force

  • supportive force from a surface

  • always drawn perpendicular to the surface


friction force

  • static

  • kinetic


Buoyoany force

  • a floating force from a fluid, eg gases and liquids

    • contact foce

    • has its own equation