In class, we did a lab in which we were to find the density of a BB, and then use the density to determine the composition of the BB’s. We decided that since Density=Mass/Volume, we would need to find the mass and density of the BB’S. We decided use the water displacement method in order to calculate the mass and volume of the BB’s, as they are round and cannot be placed together in a container without any gaps.
We measured our graduated cylinder with water up to 20mL, and massed the cylinder with water in it using a scale. This would give us an amount to subtract from our final measurements to factor out the weight of the cylinder and water.
We then filed the cylinder with BB’s until the water measured at 25mL, and massed it. In this way, we would know the volume of the BB’s was at about 5mL, and their mass would be the measurement with the BB’s minus the measurement without the BB’s. We then repeated this produces at 30mL and at 35mL, in order to have a mass for the BB’s at 10mL and 15mL as well.
After calculation our data, and comparing it to the densities of the most possible candidates for the composition of the BB’s, We determined they must be composed of steel or iron, who both have a density of 7.850.
However,this conclusion was not very accurate. This is because in our measurements, we went to the hundredth decimal place, rather than the thousandth. Although limited by our tools,