9/15/10 1 Physics 1219/15/10 2 Physics 1219/15/10 6 Physics 1219/15/10 7 Physics 121 iixrˆˆ=(where x is a length)9/15/10 8 Physics 121 it do it took to timentdisplaceme==trvdtrdv=Note: an average velocity goes with a time interval. Note: an instantaneous velocity goes with a specific time.9/15/10 9 Physics 121 vtdxdtvtxt xtttt()()()()==+ 22t (sec) x (m) t (sec) v (m) dx dt v9/15/10 10 Physics 121 t (sec) x (m) t (sec) v (m) dt v dt dx ===dttvdxxdttvdx)()(change in position over a small time interval sum (“”) in the changes in position over many small time intervals9/15/10 11 Physics 1219/15/10 12 Physics 1219/15/10 13 Physics 121 areas tvx =v =xtslopes9/15/10 14 Physics 121 <>=<>=aavtchange in velocitytime it took to make the change9/15/10 15 Physics 1219/15/10 16 Physics 121 atdvdtatvt vtttt()()()()==+ 229/15/10 17 Physics 121 t (sec) a (m/s2) dv dt t (sec) v (m/s) a 22()()()()ttdvatdtvt vtatt=+ =9/15/10 18 Physics 121 t (sec) v (m/s) d t dv t (sec) a (m/s) 2 d t a ()()dv a t dtvdvatdt===change in velocity over a small time interval sum (“”) in the changes in velocity over many small time
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