Take into account that density and relative density are given by:

Take into account that the volume associated to each of the given sustances in the table is determined by the Level Difference (because it is the change in the volume of the water of the recipient in which the substance is immersed).
The density of water in kg/m^3 is 1000 kg/m^3.
Due to the density must be given in kg/m^3, it is necessary to express the volumes of the table in m^3 and mass in kg, then, consider the following conversion factor:
1 m^3 = 1000000 ml
1 kg = 1000 g
Then, you obtain the following results:
Brass:

Cooper:
<span>The combined
gas law has no official founder; it is simply the incorporation of the three
laws that was discovered. The combined gas law is a gas law that combines
Gay-Lussac’s Law, Boyle’s Law and Charle’s Law.
Boyle’s law states that pressure is inversely proportional with volume
at constant temperature. Charle’s law states that volume is directly
proportional with temperature at constant pressure. And Gay-Lussac’s law shows
that pressure is directly proportional with temperature at constant volume. The
combination of these laws known now as combined gas law gives the ratio between
the product of pressure-volume and the temperature of the system is constant.
Which gives PV/T=k(constant). When comparing a substance under different
conditions, the combined gas law becomes P1V1/T1 = P2V2/T2.</span>
We can look at all the ages of the earth since it’s a big crack is reveals many layers of the earth and we can know about chemicals and metals that were in earth and diffrent times
Answer: 20.2 m/s
Explanation:
From the question above, we have the following data;
M1 = 800kg
M2 = 1200kg
V1 = 13m/s
V2 = 25m/s
U (common velocity) =?
M1V1 + M2V2 = (M1 + M2). U
(800*13) + (1200*25) = (800+1200) * U
10400 + 30000 = 2000u
40400 = 2000u
U = 40400 / 2000
U = 20.2 m/s