balok lembaga memiliki panjang 20cm lebar 10cm tebal 5cm massa jenis 8900g/cm3

Dik = massa jenis = 8900 g/cm³
= v = p = 20 cm
= l = 10 cm
= t = 5 cm
Dit = m ?..
Jwb = m = massa jenis ÷ V
= 8900 g/cm³ ÷ p × l × t
= 8900 g/cm³ ÷ 20 × 10 × 5
= 8900 g/cm³ ÷ 1000 cm³
= 8,9 gram