skiing over a bump

[Fu-Kwun Hwang]

This is an email message from Michael:

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) Skier´s 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?

The following is my first version of simulation for skiing over a bump.
I still need to find a way to show the difference between skiing with stiff and springy legs.
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".

Embed a running copy of this simulation
<applet code='users.ntnu.fkh.skijump3_pkg.skijump3Applet.class' archive='http://www.phy.ntnu.edu.tw/ntnujava/ejsuser/2/ejs_skijump3.jar' name='skijump34291' id='skijump34291' width='807' height='538' mayscript=true><param name='draggable' value='true'></applet>
Embed a running copy link(show simulation in a popuped window)
<a href='http://www.phy.ntnu.edu.tw/ntnujava/msg.php?smfejs=4291' target='smfejs'>Run simulation</a>

Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License

• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.

Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!

[ikuraru]

waw, I don' understand, huh...
I am sorry
-*-

[nikolo]

interesting, thanks!

[stevenfrank38]

I have started to learn simulation recently. Your post is helpful for me. But I need more help. I will ask you about it later.

Thank you..

[Judson]

I am also learning this, very interesting ... -*-

[ujkjk]

Always refreshing to hear a rational answer.
-*-

[moli.rumi]

If you want to learn how to ski bumps then you need to learn how to ski the
easiest and slowest green line route through the moguls.-*-

[danielemateriale]

hello I would like to propose a simulation, which I need so much
2D in a magnetic field that increases with the x axis, then has a maximum, and then returns to zero value as a function gaussina. see photo. the particle part in any point of this plane and with the direction to be set. also the speed and mass are to be set and charge.

on the 2D plane in the point x, y have the cmapo varies with xe, remains constant along y. you can set a starting point as the point (xo, yo) where B (tesla) is almost zero and choose the direction of the particle.

You can do the following:
1) Divide the plan, of length x and height y, in vertical strips of known width.
2) manually assign a value of the magnetic field in each strip
3)the field is constant in each vertical strip
4) manually select a point in the plane
5) manually choose a direction in the plane
6) assign charge, mass, velocity, to the particle
7) go the simulation!

then in fig1 explain what must do the program in steps. first step to divide the plane into strips of very great height and thickness of three or more mm and assign the field to each one. the field is constant in each strip but it is different from the strip and the strip. or it can be the same depending on the assignment. second step assign a point and a direction to the particle. third step, run the simulation.

in fig2 explain the graphical method for ottenre the result, in any direction goes away, the particle, the radius of curvature is always perpendicular to the direction of the particle. in the band starting the radius of curvature is constant. the particle is a portion of circumference. Now I draw the tangent line to the curve O | and the radius is perpendicalore to this line so the design and so on.

set the time in ns the lenght in mm velocity m/s field in tesla charge in coulomb mass in kg

the application is scientific to know if the particle at a given velocity and mass passes through the field or bounces back.

thanks

i can't open new topoi because a error of database

[danielemateriale]

a image of the program future

[CamKrist]

Similar subject was being discussed at yahoo answers last week. I can post the link if needed.

[harshgroom]

its christmas time merry christmas to all of you Wish you a merry christmas

[varunmix]

skiing over a bump is a good practice see here yennai arindhaal songs download can u get over it

[aran]

Wow...this is just awesome...loved the whole idea..will be writing an article on it on my personal blog very soon. It sounds too cool man.-*-

[rickytan]

nice site