Question

A physics student experimenting with a piece of plastic measures its mass to be 54.5+- 0.5g and measures its volume to be 48.8+-0.6cm3. The student has also carefully prepared four samples of salt water, each with a different density and stored in a different beaker, labeled #1 through #4. (See the table below)

Use the information to predict where the piece of plastic will sink or float in each beaker of salt water. Indicate your predictions in the table below. If for any case a conclusive prediction is not possible, state so explicitly. Explain your reasoning and show all work.

	Density of salt water in beaker	Sink, float, or inconclusive
Beaker #1	1.20 g/ml
Beaker #2	1.15 g/ml
Beaker #3	1.10 g/ml
Beaker #4	1.08 g/ml

Answer 1

density = mass/volume

density = 54.5/48.8 = 1.12 g/ml

in beaker 1 and 2 = float due to lower density

in beaker 3 and 4 = sink due to higher density