Observe Model Particles -
Load Data (Be patient.) -
- During what year did pennies change mass?
- When you include all of the minting years of pennies on the graph, how do the differing heights of the two peaks tell you which one is made of older pennies?
- Assuming pennies were originally made of 100% copper, what metal could be sandwiched inside of a copper shell to account for the newer mass of pennies? Assume that newer pennies are just a shell of copper (10%) surrounding a core of the mystery metal (90%). Densities are shown below in grams per penny volume:
- 0.93 - aluminum
- 1.6 - titanium
- 2.7 - iron
- 3.1 - nickel
- 3.1 - copper (equal in size to the mass of old pennies)
- 2.4 - zinc
- 3.6 - silver
- 2.5 - tin
- 6.7 - tungsten
- 7.4 - platinum
- 6.7 - gold
- 3.9 - lead
- Clicking the "Add background" button randomly increases each bin level by 0% to 10% of the graph height. How many clicks of "Add background" does it take to make all the penny data from 1976 to 1986 become unnoticeable?
- If you added 100 more pennies to this data set of 150, the columns would reach the top of the graph long before you could finish. Suggest two ways to change the graph that would accommodate the additional data.
- Which year is represented by the most pennies? By the second most? By the third most? What would you graph instead of mass to make these answers immediately evident?
- What is the approximate average mass of the older types of pennies?
- What is the approximate average mass of the new types of pennies?