A liquid has density 31.2 lb/ft^3; what is its specific gravity given water density 62.4?

A liquid has density 31.2 lb/ft^3; what is its specific gravity given water density 62.4?

• A. 0.50
• B. 0.49
• C. 0.60
• D. 0.55

Answer: (A)

Specific gravity is a unitless ratio that compares a liquid’s density to water’s density at the same conditions. It is found by dividing the liquid’s density by the water density: SG = rho_liquid / rho_water. Here, rho_liquid = 31.2 lb/ft^3 and rho_water = 62.4 lb/ft^3, so SG = 31.2 / 62.4 = 0.5. Since the liquid’s density is exactly half of water’s, its specific gravity is 0.5. This also shows the liquid is lighter than water.

Specific gravity is a unitless ratio that compares a liquid’s density to water’s density at the same conditions. It is found by dividing the liquid’s density by the water density: SG = rho_liquid / rho_water.

Here, rho_liquid = 31.2 lb/ft^3 and rho_water = 62.4 lb/ft^3, so SG = 31.2 / 62.4 = 0.5. Since the liquid’s density is exactly half of water’s, its specific gravity is 0.5. This also shows the liquid is lighter than water.