This is an email message from Michael:
[quote]
Dear Fu-Kwun,

I have a new simulation idea  skiing over a bump.

Pedagogical targets

a)      To show the variation of the normal force as the skier goes over a bump (undulation)
b)      To show that the skier at a certain speed becomes airborne (loss of snow contact)
c)       To show the difference between skiing with stiff and springy legs, i.e. a certain amount of suspension.

Initial variables to play with

1)      Initial speed (0 to 100 km/h)
2)      The height of the bump (10 to 100 cm)
3)      Skierīs weight (20-100 kg)
4)      Stiff/springy legs (yes or no)

The bump could comprise a segment of a circle or an ellipse to facilitate the computation. Perhaps a single step option would make it easier to follow the variation of the normal force?

Is this something that could be accomplished?
[/quote]

The following is my first version of simulation for skiing over a bump.
[s]I still need to find a way to show the difference between skiing with stiff and springy legs.[/s]
The difference between skiing with stiff and springy legs has been implemented: change the k with the slider.
Stiff legs is corresponds to larger k.  The stiffness of the leg is simulated with a spring (spring constant k).

Vx_zero is the velocity when skier move to staring point of the arc (i.e. x=0 in the simulation coordinate)
You can drag skier when the simulation is "paused".

/htdocs/ntnujava/ejsuser/2/users/ntnu/fkh/skijump3_pkg/skijump3.propertiesFull screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list