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  • Usuário do Brainly
2014-07-11T11:08:28-03:00
So = 0 m

S=vo.t+0,5.a.t²
50=5.vo + 0,5.5².a
10 = vo + 2,5.a

5=-vo/a    (Xv da parábola : xv=-b/2a )
-vo=5a
vo=-5a

-5a+2,5a=10
-2,5a=10
a=-4 m/s

vo=20 m/s

S=20t-2t²
32=20t-2t²
-t²+10t=16
-t²+10t-16=0
t²-10t+16=0

∆=10²-4.1.16
∆=100-64
∆=36

t=10+6/2
t=16/2
t=8 s




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