To calculate the density of the wooden roller, we can use the formula for density:
\[ \text{Density} = \frac{\text{mass}}{\text{volume}} \]
Given that the mass of the roller is 264 grams, we need to find the volume of the cylindrical roller.
The formula for the volume \( V \) of a cylinder is:
\[ V = \pi r^2 h \]
where \( r \) is the radius and \( h \) is the height.
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Calculate the radius: The diameter is 6 cm, so the radius \( r \) is: \[ r = \frac{\text{diameter}}{2} = \frac{6 \text{ cm}}{2} = 3 \text{ cm} \]
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Calculate the volume: \[ V = \pi (3 \text{ cm})^2 (15 \text{ cm}) = \pi (9 \text{ cm}^2) (15 \text{ cm}) = 135 \pi \text{ cm}^3 \] Approximating \( \pi \) as 3.14, we get: \[ V \approx 135 \times 3.14 \approx 423.9 \text{ cm}^3 \]
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Calculate the density: \[ \text{Density} = \frac{264 \text{ g}}{423.9 \text{ cm}^3} \approx 0.623 \text{ g/cm}^3 \]
Thus, rounding to two decimal places gives us approximately 0.62 g/cm³.
The correct answer is:
0.62 g/cm³