Calculate the density of the body?

i) A density flask is accurately weighed empty and its mass is 60.291g.lt is then carefully filled with oil up to the engraved volume on the flask being 99.98ml. The flask is re-weighed and the total mass is found to be 155.158 g. Calculate the density of the oil.

The mass of the oil is the difference of two masses.

Mass = 151.158 – 60 .291 = 90.867 grams

Density = 90.867 ÷ 99.98

This is approximately 0.91 g/ml.

The reason that oil floats on water is that oil is less dense than water.

ii) In order to calculate the density of an irregular (difficult to measure the dimensions for volume) shaped body in the lab, you are given a Balance, a hydrostatic bench, a beaker of fresh water and a box of weights to find the mass of the irregular shaped body in air and also the mass when fully immersed in water You found the mass in air to be 212.5g and when fully submerged in water, the mass was found to be 194.24g Find the density of the body

When an object is fully immersed in water, the net force is equal to the weight of the object minus the buoyant force. Since the body is fully immersed in water, the volume of the object is equal to the volume of the displaced water. To determine the mass of the displaced water, subtract the two masses.

Mass = 212.5 – 194.24 = 20.1 grams

The density of water is 1 g/ml.

V = 20.1 ml

This is volume object.

Density = 212.5 ÷ 20.1

This is approximately 10 g/ml.

iii) Evaluate the methods you used to determine the density of a solid material and the density of a liquid in the first two questions and also that of a body that floats in water.

In both case, the net force is equal to the weight of the object minus the buoyant force. To determine the volume of a solid, it must be fully immersed in water. This one difference between these two problems.

i) A density flask is accurately weighed empty and its mass is m = 60.291g.lt is then carefully filled with oil up to the engraved volume on the flask being V = 99.98ml. The flask is re-weighed and the total mass is found to be (m + M) = 155.158 g. Calculate the density of the oil.

Discounting the thickness of the flask material we assume the flask volume and the oil volume are the same. So the density of the flask is rho = m/V and the density of the flask plus oil is Rho = (m + M)/V. We are looking for M/V = rho' the density of the oil.

M = (m + M) - m = 155.158 - 60.291 = ? so we have rho' = M/V = (155.158 - 60.291)/99.98 = .949 g/ml ANS.