Jawabanmu

2014-04-15T21:55:03+07:00
M= 7,5 kg
g= 10 m/ s^{2}
A(luas penampang benda)= p × l = 6.5 = 30 m

P =  \frac{m . g}{A}
= 7,5 . 10 / 30
= 2,5

semoga membantu :)
3 4 3
2014-04-15T22:10:17+07:00
P = F/A 
F-W = 0 maka F=W = mg = 7,5.10 = 75 N
A = balok = p.l = 6.5 = 30 m²
maka P = 75/30 = 2,5 N/m²