thanks for response and additional suggestions, Gary and Asaf (and screenshots are very useful)<div><br></div><div>I'll create a worksheet for my class and post the link when done - thinking that I'll organise it into a basic, harder and advanced sections</div>
<div><br></div><div>Caroline there are already great ideas for lessons and screenshots on the physics page (added to my worksheet)</div><div><span style="font-size:11.0pt;line-height:115%;
font-family:"Calibri","sans-serif";mso-fareast-font-family:Calibri;mso-bidi-font-family:
"Times New Roman";mso-ansi-language:EN-US;mso-fareast-language:EN-US;
mso-bidi-language:AR-SA"><a href="http://wiki.sugarlabs.org/go/Activities/Physics">http://wiki.sugarlabs.org/go/Activities/Physics</a></span></div><div><font class="Apple-style-span" face="Calibri" size="4"><span class="Apple-style-span" style="font-size: 15px; line-height: 17px;"><br>
</span></font></div><div>other ideas from me: </div><div>make<span style="mso-spacerun:yes"> </span>a see saw keep moving for as long as possible
without using grab</div><div><br></div><div>for advanced students tony forster has suggested hacking physics to alter densities etc.</div><div><a href="http://wiki.sugarlabs.org/go/Modifying_Activities#Modifying_Physics">http://wiki.sugarlabs.org/go/Modifying_Activities#Modifying_Physics</a></div>
<div>Gary, would it be a good idea to link to that page from the Physics page - it took me a while to find it again</div><div><br></div><div>> We have a future Physics feature to expose the material properties, likely a simple list of material pre-sets (something like "helium" "wood", "rubber", "steel", "lead")</div>
<div><br></div><div>is water possible?</div><div>that would fit nicely with density experiments</div><div><br></div><div>how hard would it be to have a feature where mass is measured and / or displayed on the object?</div>
<div><br></div><div>cheers</div><div><br></div><div><br><br><div class="gmail_quote">On Sun, Aug 16, 2009 at 4:59 AM, Gary C Martin <span dir="ltr"><<a href="mailto:gary@garycmartin.com">gary@garycmartin.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Hi Bill,<br>
<br>
Not sure if you wanted answers :-)<div class="im"><br>
<br>
On 15 Aug 2009, at 02:51, Bill Kerr wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
I might try these next week and see how they go:<br>
<br>
does altering the size of an object affect its drop time?<br>
</blockquote>
<br></div>
No<div class="im"><br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
does joining objects together (large and small) affect drop time?<br>
</blockquote>
<br></div>
No<br>
<br>
Remember, you can run all cases at once! Just pause the simulation. Add a box right across the horizontal middle of screen. Pin it at left and right edge so it's fixed. Then across top half of screen add a large sphere, a small sphere, a couple of linked objects. Play the simulation so all shapes land on the horizontal pinned box. Pause simulation again, and delete the horizontal pinned box. Now you're all set up, shapes all aligned up for their race to the ground :-) Play!<div class="im">
<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
does altering the length of a pendulum affect its swing time?<br>
</blockquote>
<br></div>
Yes.<br>
<br>
For more advanced, you might like to try a 'split pendulum', and get to see a slow and fast swing in one cycle (some thing like the attached image works fine).<br>
<br>
<br><br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
before doing the above say what you think will happen<br>
after doing the above say whether you think the physics program reflects real world behaviour<br>
(possibility of follow up real world experiments here)<br>
</blockquote>
<br>
"possibility of follow up real world experiments here" nice :-) +1<br>
<br>
FWIW: Newton's cradle type set-ups don't work quite as expected (you end up with an oscillation of half the balls each time), I think this might be down to the default material properties we are currently using for all shapes. We have a future Physics feature to expose the material properties, likely a simple list of material pre-sets (something like "helium" "wood", "rubber", "steel", "lead").<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
design a catapult system to accurately hit<br>
(a) stationary distant target (b) moving target (c) close target<br>
<br>
build a complex or elegant building that doesn't fall down<br>
</blockquote>
<br>
A nice one here for a challenge is to restrict the design to only use circles with links. Try for an Eiffel Tower like shape. It is "World of Goo" all over again ;-)<br>
<br>
<a href="http://2dboy.com/games.php" target="_blank">http://2dboy.com/games.php</a><br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
other ideas along these lines?<br>
</blockquote>
<br>
General miscellaneous tips:<br>
<br>
- Pretty fundamental is the need to pause the simulation when constructing more complicated structures (unless you make that the challenge, build an X without pausing the simulation).<br>
<br>
- While paused, use shapes to help as 'construction templates' to help place new things accurately (they can overlap), then delete the template shape before resuming the simulation.<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
extra features I would like to see in physics:<br>
copy shapes<br>
</blockquote>
<br>
Not on our feature list, will have a think how practical this would be to actually implement.<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
move them while in setup mode<br>
</blockquote>
<br>
Been requested before already. Might be hard to implement. Don't think we have control over this in Physics, likely something down stream in either Elements, or Box2D (or all 3!).<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
a timer<br>
</blockquote>
<br>
My call on this is related to another possible future feature. Object trails would be very useful (daub a blob of paint on a shape and watch it leave a trail on screen). This 'paint daub' could be set to pulse to a timer, then you could just count the trail marks.<br>
<br>
Sound would also be great, set a specific shape to make a custom sound on any collision, set a shape to play a sound based on it's velocity (or rotation). I'd likely suggest we avoid sound until Sugar (well the various distros) have reliable stable sound (right now it seems a real mess).<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
icons:<br>
I think it would be better if the polygon icon looked like an irregular shape rather than a regular hexagon<br>
</blockquote>
<br>
Have this feature request already, you should get it in the next release :-)<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
btw if there was a regular hexagon then you could use it to do some work with tessellations in setup mode using the triangle, square, hexagon - if you had the move feature in setup mode<br>
eg. make a tessellation in setup mode and then support it so it doesn't fall apart under gravity<br>
</blockquote>
<br>
Not planning on this, but will keep it on a possible feature list.<br>
<br>
Thanks for all the great feedback so far!!<br>
<br>
Regards,<br>
--Gary<br></blockquote></div><br><br>
</div>