Calculating density activity - Free Printable

Let's solve each part of this "Calculating Density" worksheet step by step. The formula for density is:

$$
\text{Density} = \frac{\text{Mass}}{\text{Volume}} \quad \text{(D = m/v)}
$$

We'll use the water displacement method to find the volume of each object.

---

🔹 1. Rock

- Mass of rock: 20 grams
- Initial water level (before rock): 50 mL
- Final water level (after rock): 70 mL

#### Volume of rock:
$$
\text{Volume} = \text{Final} - \text{Initial} = 70\, \text{mL} - 50\, \text{mL} = 20\, \text{mL}
$$

#### Density:
$$
\text{Density} = \frac{20\, \text{g}}{20\, \text{mL}} = 1\, \text{g/mL}
$$

✔ Answer:
- Volume of rock: $70 - 50 = 20$ mL
- Density: $\frac{20}{20} = 1$ g/mL

---

🔹 2. Key

- Mass of key: 35 grams
- Initial water level: 40 mL
- Final water level: 80 mL

#### Volume of key:
$$
\text{Volume} = 80\, \text{mL} - 40\, \text{mL} = 40\, \text{mL}
$$

#### Density:
$$
\text{Density} = \frac{35\, \text{g}}{40\, \text{mL}} = 0.875\, \text{g/mL}
$$

✔ Answer:
- Volume of key: $80 - 40 = 40$ mL
- Density: $\frac{35}{40} = 0.875$ g/mL

---

🔹 3. Sharpener

- Mass of sharpener: 15 grams
- Initial water level: 50 mL
- Final water level: 60 mL

#### Volume of sharpener:
$$
\text{Volume} = 60\, \text{mL} - 50\, \text{mL} = 10\, \text{mL}
$$

#### Density:
$$
\text{Density} = \frac{15\, \text{g}}{10\, \text{mL}} = 1.5\, \text{g/mL}
$$

✔ Answer:
- Volume of sharpener: $60 - 50 = 10$ mL
- Density: $\frac{15}{10} = 1.5$ g/mL

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✔ Final Answers Summary:

#### 🪨 Rock:
- Mass: 20 g
- Volume: $70 - 50 = 20$ mL
- Density: $\frac{20}{20} = 1$ g/mL

#### 🔑 Key:
- Mass: 35 g
- Volume: $80 - 40 = 40$ mL
- Density: $\frac{35}{40} = 0.875$ g/mL

#### 🖋️ Sharpener:
- Mass: 15 g
- Volume: $60 - 50 = 10$ mL
- Density: $\frac{15}{10} = 1.5$ g/mL

---

💡 Explanation:

This worksheet teaches how to calculate density using the water displacement method to find volume. Objects are placed in a graduated cylinder filled with water, and the change in water level gives their volume. Then, density is calculated using the formula:

> Density = Mass ÷ Volume

This helps determine how tightly packed matter is in an object. For example, the sharpener is denser than the key, meaning it has more mass per unit volume.

Let me know if you'd like a printable version or visual guide!