About the Database
Concepts in Physics
To give an example of the knowledge areas the pdb will focus on, here is a classic example of conservation of angular momentum. The concept is demonstrated by an ice skater who controls their speed by extending or pulling in their arms. When the skater pulls in his or her arms, their moment of inertia is decreased.
Thus, in order for angular momentum L to be conserved, if a skater changes shape by extending or lowering their arms, their rotational speed must decrease or increase, respectively.
ΔL = 0
The two videos below demonstrate this phenomenon. Conservation of angular momentum is applied to solving many physics problems. Examples include those involving orbiting planets, gravitation, motion of atoms and subatomic particles.
Chris, a graduate student in the Department of Physics and Astronomy at the University of Hawaii Manoa, demonstrates conservation of angular momentum.
Mechanical engineering junior at the University of Hawaii Manoa, Ana, demonstrates conservation of angular momentum.
Project Leads of the Physics Database of Problems

Dr. Mark Slovak

Christina Nelson
For more about this project, see their project page: College Physics