Jawabanmu

2014-05-28T17:07:05+07:00
 \frac{F1}{A1} =  \frac{F2}{A2}
 \frac{1420}{1/4 π d}  \frac{F2}{1/4 π d}
 \frac{1420}{0,01}  \frac{F2}{0,04}
F2= 5680 N
2014-05-28T23:14:43+07:00
P1 = P2
F/r² = F/r²
1420 N / 100= F/1600
1420.16 = F2
22720 N

Maka massa benda yang diangkat
F = m. a
22720 = m . 10
2272 kg = m

:)