We have the following equation:
D = m / V
Where,
m: mass
V: volume
D: density.
The volume of the rectangular prism is:
V = (5) * (10) * (8)
V = 400 cm ^ 3
For Lead:
m = D * V
m = (11.36) * (400)
m = 4544 grams
For Iron:
m = D * V
m = (7.87) * (400)
m = 3148 grams
The difference of the masses is:
4544 - 3148 = 1396 grams
Answer:
The mass of the prism made of lead is 1396 grams than the one made of iron