Jawabanmu

2013-12-14T02:38:45+07:00
F = m.a
m = F/a = 7000/3,5 = 2000 kg
1 4 1
2013-12-14T04:26:19+07:00
F = m . a 
m =  \frac{F}{a}
m =  \frac{7000}{3,5} = 2000kg :)
1 4 1