Worksheet with practice problems on density, mass, and volume.

1. Density = Mass / Volume
Density = 45 g / 15 cm³
Density = 3 g/cm³
$\boxed{3 \text{ g/cm}^3}$

2. Density = Mass / Volume
Density = 60 g / 30 cm³
Density = 2 g/cm³
$\boxed{2 \text{ g/cm}^3}$

3. Rock 2 is heavier because it has a greater mass (60 g) compared to Rock 1 (45 g). Rock 1 is lighter because it has a smaller mass.

4. Rock 1 is more dense because its density is 3 g/cm³, which is higher than Rock 2’s density of 2 g/cm³. Rock 2 is less dense because its density value is lower.