Unit-7 Density and Temperature
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Unit-7 Density and Temperature
Answer: Density is the mass of a substance present in a unit volume, given by rho = mass/volume.
Answer: Density = mass/volume = 5/2 = 2.5 kg/m^3.
Answer: Density = 96.5/5 = 19.3 g/cm^3, which is the known density of gold.
Answer: In SI, mass is in kg and volume in m^3, so density is measured in kg/m^3.
Answer: Air is very light; its density at sea level is only about 1.29 kg/m^3.
Answer: 1 g/cm^3 = 1000 kg/m^3, since 1 g = 0.001 kg and 1 cm^3 = 10^-6 m^3.
Answer: Multiply by 1000 to convert g/cm^3 to kg/m^3, so 0.5 g/cm^3 = 500 kg/m^3.
Answer: Multiply g/cm^3 by 1000 to convert to kg/m^3, so 0.8 g/cm^3 = 800 kg/m^3.
Answer: Pure water has maximum density of 1000 kg/m^3 at 4 degrees C.
Answer: Density = 600/1000 = 0.6 g/cm^3, which is why wood floats in water.
Answer: The fraction submerged equals the relative density, 0.9/1 = 0.9.
Answer: Relative density compares the density of a substance with the density of water at 4 degrees C.
Answer: Density = 8/2 = 4 kg/m^3.
Answer: New density = (2m)/(V/2) = 4(m/V), so the density becomes four times.
Answer: Since it is a ratio of two densities, relative density has no unit.
Answer: For equal volumes, density = mass/volume is greater for the object with greater mass.
Answer: Density = 250/100 = 2.5 g/cm^3.
Answer: Mass = density x volume = 3 x 50 = 150 g.
Answer: Volume = mass/density = 4000 g / 2 g/cm^3 = 2000 cm^3.
Answer: Objects with density lower than water float because they displace their own weight of water.