Work-Energy Theorem
Work done on an object shows up directly as a change in its kinetic energy. This simulation applies a force over a distance and tracks both quantities, so the theorem can be checked numerically as the motion proceeds.
How to use this simulation
- Apply forces of different magnitudes and directions
- Change the distance over which the force acts
- Read the work done and the kinetic energy together
What to look for
- Net work done always matches the change in kinetic energy
- A force at right angles to the motion does zero work
- Negative work, from friction or braking, reduces kinetic energy
The physics behind it
Work is W = Fd·cosθ, counting only the force component along the displacement. The work–energy theorem states that the net work equals the change in kinetic energy, W = ½mv² − ½mu². A force perpendicular to the motion does no work at all, which is why the centripetal force in circular motion never changes the speed.