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Ch.1 - Introduction: Matter, Energy, and Measurement
Chapter 1, Problem 103

U.S. 1-cent coin (a penny) has a diameter of 19 mm and a thickness of 1.5 mm. Assume the coin is made of pure copper, whose density and approximate market price are 8.9 g/cm3 and $2.40 per pound, respectively. Calculate the value of the copper in the coin, assuming its thickness is uniform.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Density

Density is defined as mass per unit volume and is a crucial property of materials. In this context, the density of copper (8.9 g/cm³) allows us to calculate the mass of the penny once its volume is determined. Understanding how to convert between units of measurement, such as from mm³ to cm³, is essential for accurate calculations.
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Volume of a Cylinder

The penny can be approximated as a cylinder, and its volume can be calculated using the formula V = πr²h, where r is the radius and h is the height (or thickness). This geometric understanding is vital for determining how much copper is present in the coin, which directly influences its mass and value.
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Conversion of Units

In this problem, converting units is necessary to find the value of copper in the penny. The mass of copper needs to be converted from grams to pounds to match the market price given in dollars per pound. Mastery of unit conversion ensures that calculations are consistent and accurate, allowing for the correct determination of the coin's value.
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