Sink or Float Experiment < Crafty-Mummy - Free Printable

To solve the problem of predicting whether each object will sink or float, we need to consider the density of each object relative to water. Objects with a density less than water will float, while objects with a density greater than water will sink.

Key Points:

1. Density of Water: The density of water is approximately \( 1 \, \text{g/cm}^3 \).
2. Buoyancy Principle: An object floats if its average density is less than the density of water; otherwise, it sinks.

Analysis of Each Object:

#### 1. Egg
- Eggs have a density slightly greater than water (approximately \( 1.03 \, \text{g/cm}^3 \)).
- Prediction: Sink

#### 2. Pencil
- Pencils are made primarily of wood and graphite.
- Wood has a density less than water (typically around \( 0.6 \, \text{g/cm}^3 \)), but the graphite and other materials can increase the overall density.
- However, most pencils are designed to float due to their hollow structure and low overall density.
- Prediction: Float

#### 3. Spoon
- Spoons are typically made of metal (e.g., stainless steel or aluminum).
- Metals like stainless steel have a much higher density than water (e.g., \( 7.8 \, \text{g/cm}^3 \) for steel).
- Prediction: Sink

#### 4. Blue Sphere
- The blue sphere appears to be a ball, likely made of rubber or plastic.
- Rubber and many plastics have densities less than water (e.g., rubber is around \( 0.9 \, \text{g/cm}^3 \)).
- Prediction: Float

#### 5. Rock
- Rocks generally have a high density, often much greater than water (e.g., granite has a density of about \( 2.7 \, \text{g/cm}^3 \)).
- Prediction: Sink

#### 6. Coin
- Coins are made of metals such as copper, nickel, or zinc.
- These metals have densities much greater than water (e.g., copper has a density of \( 8.96 \, \text{g/cm}^3 \)).
- Prediction: Sink

Final Predictions:

| Object | Sink | Float |
|--------------|------|-------|
| Egg | X | |
| Pencil | | X |
| Spoon | X | |
| Blue Sphere | | X |
| Rock | X | |
| Coin | X | |

Explanation:

- Egg: Sinks because its density is slightly greater than water.
- Pencil: Floats because its overall density is less than water due to its hollow structure and lightweight materials.
- Spoon: Sinks because it is made of metal, which has a high density.
- Blue Sphere: Floats because it is likely made of a material with a density less than water.
- Rock: Sinks because rocks generally have a high density.
- Coin: Sinks because it is made of metal, which has a high density.

Final Answer:

\[
\boxed{
\begin{array}{|c|c|c|}
\hline
\text{Object} & \text{Sink} & \text{Float} \\
\hline
\text{Egg} & \checkmark & \\
\hline
\text{Pencil} & & \checkmark \\
\hline
\text{Spoon} & \checkmark & \\
\hline
\text{Blue Sphere} & & \checkmark \\
\hline
\text{Rock} & \checkmark & \\
\hline
\text{Coin} & \checkmark & \\
\hline
\end{array}
}
\]