## The Anatomy of Black Holes - Page 16

- Calculate the density. Remember that density is defined as mass/volume.
- Given what you know about black holes, how small must the radius be in order for the collapsed star to become a black hole? What would the density be at that point? Show your calculations below.

- Summarize by comparing the value for the density of material your collapsed star would have at the point it became a black hole to common items. What is the value of the density of the densest thing you can find here on Earth? Given the value you found for your aluminum foil star, what can you say about matter inside a collapsing star as it becomes a black hole?