Experimental work is an integral part of introductory college-level courses such as the AP Physics courses. Although excellent physics learning can take place using the simplest equipment, the integration of laboratory activities with classroom work requires careful balancing between time allocation and budget restrictions.

Web technology can be a powerful tool for learning physics concepts and developing skills of measurement, analysis, and processing information. Virtual labs and simulations should not substitute for laboratory experience, but may be used to supplement and extend such experience.

You can use these simulations in the classroom to help the students visualize concepts or as virtual lab activities.
PHYSICS SIMULATIONS

PhET. Physics Education Technology
Project at the University of Colorado includes over 50 excellent simulations on various areas of Mechanics, Waves and Electricity and Magnetism. The website has a searchable database of activities that integrate the use of the simulations. The simulations can be downloaded in its entirety for free!

Physics Applets and Animations by Topic
Excellent list compiled by Frank Noschese

AP Central: Physics Web Guide
The AP Physics Web Guide includes links and brief descriptions of simulations for every single topic of the AP Physics (B and  C) curriculum.

Physics Simulation Library
Collection of simulations from Interscience-Wiley to accompany Halliday Resnick 6ed. Each simulation includes audio and self-tests.

ActivPhysics
This is a very comprehensive resource to accompany University Physics by Young & Freedman. It includes not only excellent simulations with quantitative analysis but also videos in a wide variety of topics from Mechanics, Waves/Acoustics, Thermodynamics, Optics, Electromagnetism and modern Physics.

Virtual Labs and Simulations by Gary Richert
Collection of links organized by topic to sites on the web that have computerized simulations of physics principles. Includes links to lecture notes by topic. This site is not maintained regularly and has lots of broken links.

General Physics Java Applets by  B.Surendranath Reddy
Excellent quality JAVA applets in Mechanics, Waves, Optics and
a few in Electricity and Magnetism.

Java Applets on Physics
42 simulations by Walter Fendt. Includes Mechanics, Oscillations and Waves, Electrodynamics, Optics, Thermodynamics and Relativity.
These applets can be downloaded for free!

ie-Physics
Internet based experimental physics: contains several experiments with historical backgrounds of original discoveries.

Contemporary College Physics Simulation Library
This group of simulations is related to Jones & Childers textbook. Consists of 56 simulations accompanied by instructions and explanations.

PHYSLETS: Scripted by Andrew Duffy at Boston University.
Contains excellent Physlet exercises divided in  three main collections: first and second semester introductory physics classes and pre-lab assignments.

Essential  Physics Activities on a Budget Price
Dr. Joel Bryan. Texas A&M University
Contains 36 simple physics labs downloadable in WORD and pdf files.

Electricity and Magnetism Java Tutorials
Molecular Expressions from Florida State University
Great tutorials with animations. Includes: magnetic fields, capacitors, electromagnetic induction, Lenz's Law, ac and dc generators, lightning, cathode rays, how a CD works, how a hard drive works and how a metal detector works.

Optics Interactive Tutorials
Molecular Expressions from Florida State University
Great tutorials with animations. Includes topics in light and optics such as reflection, refraction, image formation in mirrors and lenses, interference and diffraction, polarization, color and human vision.

Physics Lessons:i-Physics
Includes a compilation of 69 interactive lab simulations from various sources.

Physics Simulations
Collection from Mississippi State University. This site includes links to Java and Shockwave simulations from around the world. Covers all topics of AP Physics B. Most of the simulations are placed on their server.

Learn Physics Through Playing JAVA
These applets were developed by C.G. Ng in Hong Kong. The topics covered are Mechanics, Light and Waves and Electricity   and Magnetism.

Interactive Physics with JAVA
21 simulations by Sergey and Tanya Kiselev. Topics include Light and Optics, Pendulum, Springs and DC Circuits.

Virtual Laboratory
Physics applets from the University of Oregon. Includes Energy, Mechanics and Thermodynamics topics.

The Physics Ancillary
Judson Wagner created physics applets that offer visual representation
of concepts in all topics of the AP Physics syllabus.

Computer Animations of Physical Processes
The topics covered are Waves, Optics, Mechanics and Thermodynamics. Each topic includes a series of very colorful animations divided into mini- lectures and video clips.

Physics 2000
University of Colorado. This site has simulations from Atomic and Nuclear Physics.

PhysicsWeb: Interactive Experiments
Very extensive collection of links for college levels of physics.

Interactive Physics Simulations
Short collection of  simulations written by A. John Mallinckrodt using Interactive Physics from MSC Working Knowledge.

The Physics Illuminations
Contains simulations for topics in Kinematics, Dynamics and Vectors.