# Week 2 – Mass & Volume Relationships

#### Monday:

Volume = the amount of space an object takes up.

Volume can be measured using a graduated cylinder (for fluids) or water displacement (for irregular solids).  For regular geometric solids, you can calculate the volume using an appropriate equation.

Rectangular Prism:  V = l·w·h

Cylinder:  V = π·r2·l

Units:  Graduated cylinders are marked in milliliters (ml).  Using the equation with lengths in centimeters (cm), they would produce a volume in cubic centimeters (cm3).  Based on our measurements of volume in cm3 and ml, we discovered that 1 ml = 1 cm3.

#### Tuesday:

We measured the mass and volume of several pieces of steel and aluminum.

Analysis:

* Graph this data on your lab packet.  Determine the slope of each line.

Conclusions:

* The slope represents the substance’s density.  It tells us how much mass (g) there is in each unit of volume (ml or cm3), so units of density are either g/ml or g/cm3.

We also discovered that more dense things tend to sink and less dense things tend to float.  Water’s density is 1.0 g/ml, so steel and aluminum both sink in water.  Foam’s density is about 0.08 g/ml, so it floated on water.  Air’s density is somewhere around 0.0012 g/ml, so air floats above water.

#### Homework:

We did large parts of these worksheets in class.  Finish the remainder for Monday.

Practice Worksheet – Week 2

LabPacket – Week 2