Jawabanmu

2014-05-25T16:53:35+07:00
Rumus : 1/2 m.vkuadrat
1/2 20.3kuadrat
1/2 20.9 = 20:2 = 10
10x9 =90 J

2014-05-25T16:53:48+07:00
EK= 1/2.M.V²
EL= 1/2.20 kg.3²ms= 90 Joule