Enter the initial water level, final water level, and mass of the object into the calculator to determine the density of the object.
Water Displacement Formula
The following formula is used to calculate density from water displacement.
D = m / (FW - IW)
- Where D is the density g/cm^3
- m is the mass in grams
- FW is the final water level (mL)
- IW is the initial water level (mL)
Water Displacement Definition
Water displacement is defined as the density of an object calculated through the displacement of a certain amount of water.
Water Displacement Example Problem
How to calculate water displacement?
The following example explores how to calculate the density of an object using the water displacement method. In this case, an irregularly shaped object is placed in a container of water and the displacement is measured.
First, determine the mass of the object in grams.
For this example problem, the mass of the object is measured to be 500 grams.
Next, measure the initial water level before the object is placed into the container.
In this case, the water level is at 400 mL prior to anything being added to the water.
Next, place the object into the water and record the final water level.
For this example, the final water level is measured to be 500 mL.
Finally, calculate the density using the formula above:
D = m / (FW – IW)
D = 500 / (500 – 400)
D = 5 g/cm^3
Even though the water displacement is measured in mL, these units are equivalent to centimeters cubed, so the final result can be expressed in grams per cm^3 or mL.
FAQ
Why is water displacement used to measure density?
Water displacement is used to measure density because it provides a simple and accurate way to determine the volume of irregularly shaped objects, which can be difficult to measure by other means. By knowing the volume and the mass of the object, the density can be calculated easily.
Can water displacement be used for all types of materials?
Water displacement can be used for most solid materials that do not absorb water and are denser than water, so they sink. It is not suitable for materials that dissolve in water or are so light that they float.
How accurate is the water displacement method?
The accuracy of the water displacement method depends on the precision with which the initial and final water levels are measured. It also requires that the object does not dissolve or react with water. With careful measurement, it can provide very accurate results.
Can the water displacement method be used to find the density of a liquid?
While the water displacement method is primarily used for determining the density of solid objects, a modified version of the method can be employed to find the density of a liquid by measuring the displacement caused by an object of known volume and density.
