Question

A stack of 10 pennies weighing 26.55 grams is placed in a graduated cylinder containing water. The initial volume of water is 50.0 mL and the final volume of the water and pennies 53.3 mL. What is the density of ONE penny?

Answer 1

In order to determine the density of an item, we will need to determine its mass and volume. The standard unit for measuring mass in a lab is the gram. Think about liquids- what units do you typically report the volume of a liquid in? What about for a sugar cube, what volume is the most appropriate?
A regular object like a sugar cube can be measured with a ruler so we might report the volume in centimeters cubed (cm3). An irregular object like the plate pictured below can be measured by using a technique called volume by displacement. A liquid (typically water) is placed in a graduated cylinder and the volume of a liquid is measured. Then the irregular object is placed in the liquid and the volume is measured again. The change in volume is the irregular object’s volume. This measurement is often made using a graduated cylinder and recording a volume in Liters or milliliters (mL).
Figure 1. (a) Regular object of metal blocks with the same width, length, and height. (B) An irregular