The following applet shows how an impulse will affect the trajectory(shown in green) of a particle.
[b]Initial condition:[/b]
The particle is moving in the x-direction with constant velocity.
[b]Controlable parameter:[/b]
You can modify the impulse strength and the angle of impulse relative to velocity vector(initial value is 90 degree).
Move you mouse to the impulse vector(blue arrow), Click the mouse to [b]fire[/b] the impulse, and the impulse will be applied to the particle. The motion of the particle will be changed. try to fire the impulse and find out how the trajectory and the velocity are modified by the applied impulse force (in very short but finite interval).

Virtual Physics laboratory Original URL

Fu-Kwun Hwang, Dept. Of Physics, National Taiwan Normal University.