Answers

2016-01-27T20:42:18+08:00
0 velocity because it reached the maximum height.
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2016-02-01T17:22:03+08:00
taking height as h ; accelaration due to gravity as g ; initial velocity as u ; and final velocity as v
formula chosen: 2gh = v square - u square
h= 20.1
g= 9.8 m/s2
u= 12.8 m/s

2 gh = v2 - u2
2 x 9.8 x 20.1 = v2 - 12.8square
19.6 x 20.1 = v2 - 12.8 x 12.8
393.96 = v2 - 163.84
393.96 + 163.84 = v2
557.8 = v2
therefore v = the root of 557.8
which is a long calculation but if u use a calculator u'll get 23.61

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