10. Compare the masses of the pennies measured in Part D. Are all of the masses the same, within the limits of uncertainty in the balance measurement? Are there apparent differ- ences based on when the pennies were minted? 1. How does the mass of a penny minted in 1982 or before compare with the mass of newer pennies. Try to explain the difference.

10. Compare the masses of the pennies measured in Part D. Are all of the masses the same, within the limits of uncertainty in the balance measurement? Are there apparent differ- ences based on when the pennies were minted? 1. How does the mass of a penny minted in 1982 or before compare with the mass of newer pennies. Try to explain the difference.