2022-09-19 - SI Units and Center of Mass analysis#

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SI Units#

Different units are used as a standard measurement; there is so much that can be measured, so there are many different unitsto be used accordingly

  • units used depends on what is being measured, what the measurement is for, the person measuring it, location, etc.

(Standard Internationality)

  • meter = the length of the path travelled by light in a vacuum during a time interval of 1/299,792,458 of a second

    • this definition used for maximum precision

  • seconds = measured from radioactive oscillation of cesium

  • base numbers that everything is measured in

  • imperial system is meant to use easily factorable numbers (12, 60) for everyday use (not necessarily scientific)

  • 1 liter of water weighs 1 kg (kg is standard unit for mass)

  • 1L = 1000g/1000mL/1000cm^3

  • 0K impossible to achieve

  • 0K=-273C/32F

Center of Mass - for the study of human movement#

  • mass never changes, but pounds do based on gravitational force

    • mass = the “stuff inside you” (kg)

  • pounds are a measure of force against the ground

  • Newton’s Laws

    • Newton’s First Law: inertia, objects in motion stay in motion unless acted upon by an external force

    • Newton’s Second Law: Force = Mass x Acceleration

    • Newton’s Third Law: for every action there is an equal and opposite reaction

  • kgm/s^2= Newton!

  • derived from SI units, keep building up from base level things

Try to collect some data#