Basic physics notes PDF

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Grade 12 physics notes...

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MOVEMENT'AND'POSITION'' ' ' SPEED% % • Speed%is%a%term%is%used%in%everyday%life.in% our%daily%day%life%many.%High-speed%chases% fatal%accidents%on%the%road.% % This%chapter%is%about%how%speed%defined%and% measured%% % • The%speed%is%based%on%acceleration%and% deceleration%and%we%can%find%speed%by% using%velocity-time%graph%and%can%find% acceleration%of%an%object%and%we%can%find% how%far%an%object%has%traveled%by%using% velocity-time%graph%% % Equation%of%Speed%% % • SPEED%=%distance%travelled%% !!!!!!!!!!!!!!!!!!!!!!!!!!!!Time%taken%% %%%%%%%%%%

• V=D% %%%%%T% % Symbols%% %%%%%%%%%%%%%V=%speed%or%velocity%% %%%%%%%%%%%%%D=%distance%% %%%%%%%%%%%%%T=%time%% % %

UNITS&OF&SPEED&& & • Distance%measured%in%meters%time%taken%in% seconds% so% until% of% speed% would% be% in% meters% per% second% in% symbols% (M/S).And% other% units% can% be% used% for% speed% such% as% kilometers% per% hour% in% Symbols% (KM/H)% or% centimeters% per% seconds% (CM/S).And% you% can%measure%speed%in%miles%per%hour%(MpH)% in%exam%questions%should%be%in%metric%units% so%remember%that% M%is%the%abbreviation%for% meters%and%not%miles%%

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Rearranging!the!speed!equation!! ! ! The!speed!equation!can!be!rearranged!to! give!two!other!useful!equations.! ! Distance!travelled,!D'='speed,'V'x'TIME' TAKEN,T'' ' Time'taken','t'='distance'travelled,d'' !!!!!!!!!!!!!!!!!!!!!!!!!!!!Speed%,%V%% %

! Average!speed!! ! How!to!calculate!the!average!speed!?! ! • The!total!distance!travelled!divided!by! time!taken!for!the!journey.! ! % %

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If!you!look!at!the!speedometer!in!car,!you! will!see!that!the!speed!of!the!car!changes! from!instant!to!instant!as!the!accelerator!or! Brake%is%used%.% % %%%%%%%%%The%speedometer%therefore%shows%the% instantaneous%speed%of%the%car%% %

Examples&& ! • You!can!convert!a!speed!in!m/s!into!a! speed!in!km/h'if!the!car!travels!12.8! meters!in!one!second!it!will!travel!! ! • 12.8!x!60!meters!in!60!seconds!(that!is! one!minute)!! ! • 12.8!x!60!x!60!meters!in!60!minutes! (that!is!,!1!hour!)!! !

• Which!is!46080!meters!in!an!hour!or! 46.1km!(to!one!decimal!place)! ! • We!have!multiplied!by!3600(!60!x!60!)! to!convert!from!m/s'to!m/h,!(!as!there! are!1000m!in!1km!)! ! !

Rule:&to#convert#m/s#to#km/h#simply# multiply#by#3.6# %...