Respostas

2014-08-11T18:57:19-03:00
-----------------------Item A-----------------------

v(t)=vo+a*t

8=0+a*20

a=8/20=0,4m/s^2

-----------------------Item B-----------------------

v^2=vo^2+2*a*AB

8^2=0^2+2*0,4*AB

64=0,8*AB

AB= \frac{64}{0,8}=80m

v^2=0^2+2*0,4*180

v^2=144

v= \sqrt{144}

v=12m/s
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