Problem
US coins are roughly in the shape of cylinders. Therefore, the formula for the volume of a cylinder can be used to compare the volumes of coins. How does the combined volume of pennies compare to the volume of 1 presidential dollar? The volume of 3 pennies is choose your answer... than the volume of 1 presidential dollar by approximately type your answer... \( \mathrm{mm}^{3} \). (Express your answer as a decimal to the nearest tenth.)
Solution
Step 1 ：Find volume of 1 penny: \( V_{p} = \pi r_{p}^2 h_{p} \)
Step 2 ：Find volume of 1 presidential dollar: \( V_{d} = \pi r_{d}^2 h_{d} \)
Step 3 ：Compare combined volume of 3 pennies to 1 presidential dollar: \( \frac{3V_{p}}{V_{d}} \) and find the difference in volumes
