Density Formula - Free Printable

Problem Overview:

The task involves defining density and identifying which objects in each pair are more dense than the other. Let's break this down step by step.

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Step 1: Define Density

Density is defined as the mass of a substance per unit volume. Mathematically, it is expressed as:

\[
\text{Density} = \frac{\text{Mass}}{\text{Volume}}
\]

This means that density measures how tightly packed the particles of a material are. Materials with higher densities have more mass in a given volume compared to materials with lower densities.

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Step 2: Compare Objects in Each Pair

We need to determine which object in each pair is more dense. Here are the pairs and their comparisons:

#### Pair 1: Styrofoam ball vs. Rock
- Styrofoam ball: Made of polystyrene foam, which is very lightweight and has a low density.
- Rock: Typically made of minerals like granite or limestone, which are much heavier and have a high density.
- Conclusion: The rock is more dense than the styrofoam ball.

#### Pair 2: Water vs. Ping pong ball
- Water: A liquid with a density of approximately \(1 \, \text{g/cm}^3\).
- Ping pong ball: Made of lightweight plastic (e.g., celluloid) and is designed to float on water, indicating it has a lower density.
- Conclusion: Water is more dense than the ping pong ball.

#### Pair 3: Cold ring vs. Pencil
- Cold ring: Likely made of metal (e.g., iron, steel, or another dense material), which has a high density.
- Pencil: Made primarily of wood (low density) and graphite (medium density). Overall, it is less dense than a metallic ring.
- Conclusion: The cold ring is more dense than the pencil.

#### Pair 4: Water vs. Oil
- Water: As mentioned earlier, has a density of approximately \(1 \, \text{g/cm}^3\).
- Oil: Typically has a lower density than water (e.g., cooking oil has a density around \(0.9 \, \text{g/cm}^3\)).
- Conclusion: Water is more dense than oil.

#### Pair 5: Bathtub toys vs. Large log
- Bathtub toys: Typically made of lightweight plastic or rubber, designed to float on water, indicating low density.
- Large log: Made of wood, which is denser than the plastic used in bathtub toys.
- Conclusion: The large log is more dense than the bathtub toys.

#### Pair 6: Large log vs. Small rock
- Large log: Made of wood, which generally has a density around \(0.6 \, \text{g/cm}^3\) to \(0.9 \, \text{g/cm}^3\).
- Small rock: Made of minerals, which are typically denser than wood (e.g., granite has a density around \(2.7 \, \text{g/cm}^3\)).
- Conclusion: The small rock is more dense than the large log.

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Step 3: Mark the More Dense Object

Based on the comparisons above, mark an "X" on the more dense object in each pair:

1. Styrofoam ball vs. Rock: X on Rock
2. Water vs. Ping pong ball: X on Water
3. Cold ring vs. Pencil: X on Cold ring
4. Water vs. Oil: X on Water
5. Bathtub toys vs. Large log: X on Large log
6. Large log vs. Small rock: X on Small rock

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Final Answer

\[
\boxed{
\begin{array}{c}
\text{Density} = \frac{\text{Mass}}{\text{Volume}} \\
\text{Markings:} \\
\text{Rock, Water, Cold ring, Water, Large log, Small rock}
\end{array}
}
\]