HELP

The Parameter-Panel

4 Select Buttons at Top of Panel: Select the type of demonstration you want to see.
Stop: Stops moving.
Start: Starts moving.
Water Flow: Put the cursor into the text field and change water supply rate at your will. To make your change active, press "ok". Flow rate is given in g/s (grams per second). For the FH-waterwheel, a bucket contains a maximum of 3670 g, i.e. it will be full in 10 s when flow rate is put to 367 g/s. The simulation will give you a somewhat longer time, because a part of the water is leaking out. Without supply, a bucket will become empty in 81 seconds.
Brake: Brake strength in Js (Joule seconds). If set to zero, the waterwheel dissipates no energy and will turn more and more quickly. The brake strength multiplied with the angular velocity is the torque excerted by the brake. The brake-torque is thus proportional to angular velocity "omega".
Reset: Press reset to repeat a demonstration.
ok: Activates parameters you changed.
Picture on/off: Toggles the background picture.
Kick + 0.5 Hz: Applies a clockwise "kick" which increases angular velocity by 0.5 Hz. Angular velocity is defined by 2*3.14159/T with T = time for one turn. Is has therefore the units of 1/s or Hz (Hertz).
slower: Slows simulated time. Pressing 4 times this button results in the simulation running with half speed.
faster: Accelerates simulated time. Pressing 4 times this button results in the simulation running with double speed. However, speed will increase only if your computer is enough powerful to perform all necessary mathematics in a shorter time.
Button "display only every second time step": To reduce the number of operations your computer has to perform, the picture is refreshed only after every second time step. This measure sometimes helps to reduce irregularities (jumps) in the displayed movement. You have to try out the best combination of speed factor and refresh rate, because quality of performance depends on your hard- and software (e.g. Netscape performs much better than the Internet Explorer).

Problems

I lost the Parameter Control Panel: It may be behind the waterwheel- window. If you don't find it, go back to the main menue and start the Applet again.
The waterwheel makes jumpy and irregular movements: The program works best on a PC with 266 MHz Pentium (or faster) and Netscape Navigator 4.0 or higher. You can smooth the movement by trying out the best combination of speed factor and refresh rate (see above). Quality of performance depends on your hard- and software. Try another type or version of browser if the problem persists.
Other Problems: I am not aware of other problems, but in case you have such, please ask me by e-mail: gassmann@psi.ch

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