The weight of the iron bar is 2 kg. Determine the mass of a gold bar of the same size.

Index 1 – iron; 2 – gold
Iron density = 7800 kg / m3
Gold density = 19320 kg / m3
Mass is calculated by the formula m = p * v, where v is volume and p is density
The volumes are the same, v = m / p
m1 / p1 = m2 / p2
Multiplying the cross by the cross
p1 * m2 = m1 * p2
m2 = m1 * p2 / p1 = 2 * 19320/7800 = 4.95 kg
Answer: 4.95 kg