Wikimedia
Wikipedia: The Black Hole
This site examines the black hole as an object in astrophysics. Delve into this comprehensive resource that covers this concept from its history, to qualitative physics, the reality of black holes, mathematical physics and more.
PBS
Pbs: A Classical and Relativistic Trip to a Black Hole
This PBS site is a classroom activity that takes a trip to a black hole. Students apply calculations on distance, velocity, acceleration, time, circular motion, density, and more.