Question

The R.D. of lead is 11.34. Find its density in S.I. unit.

Answer 1

Answer: Density = 11340 kg/m³.

Explanation:

We know,

Specific Gravity or relative density = (Density of object)/(Density of water at 4° C)

=> d/(1000 kg/m³) = 11.34

=> d = 11.34 × 1000 kg/m³

=> d = 11340 kg/m³.

Therefore, density of lead is 11340 kg/m³.

Tip:

• RD has no dimension. It is used to compare the density of the object with that of water. It is a ratio or a simple method to make an idea about the mass (density) of the object.
• Archimedes principle states that if a body is partially or fully immersed in a fluid, it receives an upthrust which is equal to the weight of the fluid so displaced. Lactometre, and hydrometre are dependent on it.
• A body inside a fluid, faces a pressure which is equal to $h \rho g + P_{0}$, where Po is atmospheric pressure.