Class notes phy 101 (psyc 101)

‭1.‬‭Kinematics‬‭(The‬‭Study‬‭of‬‭Motion)‬
‭Kinematics‬‭describes‬‭how‬‭things‬‭move‬‭without‬‭worrying‬‭about‬‭why‬‭(forces).‬

‭‬ D
● ‭ isplacement‬‭(Δx):‬‭The‬‭change‬‭in‬‭position‬‭(not‬‭the‬‭same‬‭as‬‭distance).‬
‭●‬ ‭Velocity‬‭(v):‬‭The‬‭rate‬‭of‬‭change‬‭of‬‭displacement‬‭(m/s).‬
‭●‬ ‭Acceleration‬‭(a):‬‭The‬‭rate‬‭of‬‭change‬‭of‬‭velocity‬‭(m/s2).‬

‭The‬‭Big‬‭Three‬‭Equations‬‭(for‬‭constant‬‭acceleration):‬

‭ .‬ v
1 ‭ f​=vi​+at‬
‭2.‬ ‭Δx=vi​t+21​at2‬
‭3.‬ ‭vf2​=vi2​+2aΔx‬




‭2.‬‭Dynamics‬‭(Newton’s‬‭Laws‬‭of‬‭Motion)‬
‭Dynamics‬‭explains‬‭why‬‭things‬‭move‬‭using‬‭Forces‬‭(F)‬‭.‬

‭●‬ N ‭ ewton’s‬‭1st‬‭Law‬‭(Inertia):‬‭An‬‭object‬‭stays‬‭at‬‭rest‬‭or‬‭in‬‭motion‬‭unless‬‭acted‬‭upon‬‭by‬‭a‬
‭net‬‭force.‬
‭●‬ ‭Newton’s‬‭2nd‬‭Law‬‭(The‬‭Big‬‭One):‬‭The‬‭acceleration‬‭of‬‭an‬‭object‬‭is‬‭directly‬‭proportional‬
‭to‬‭the‬‭net‬‭force‬‭and‬‭inversely‬‭proportional‬‭to‬‭its‬‭mass.‬
‭∑F=ma‬
‭●‬ ‭Newton’s‬‭3rd‬‭Law:‬‭For‬‭every‬‭action,‬‭there‬‭is‬‭an‬‭equal‬‭and‬‭opposite‬‭reaction.‬

‭ ote:‬‭Always‬‭draw‬‭a‬‭Free‬‭Body‬‭Diagram‬‭(FBD)‬‭.‬‭This‬‭is‬‭a‬‭simple‬‭sketch‬‭where‬
N
‭you‬‭represent‬‭the‬‭object‬‭as‬‭a‬‭dot‬‭and‬‭draw‬‭all‬‭force‬‭vectors‬‭(Gravity,‬‭Normal‬‭Force,‬
‭Friction,‬‭Tension)‬‭pointing‬‭away‬‭from‬‭it.‬