Jawabanmu

2014-02-28T17:56:16+07:00
Ek = 1/2 . m . v²
= 1/2 . 50 kg . (20m/s)²
= 1/2 . 50 . 400
= 10000 Joule
2014-02-28T17:57:43+07:00
Ek = 1/2 × m × v²
     = 1/2 × 50 kg × 20²
     = 1/2 × 2000
     = 1000 J