[IAEP] Physics - Lesson plans ideas?
Asaf Paris Mandoki
asafpm at gmail.com
Sat Aug 15 22:11:11 EDT 2009
> 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
> is water possible?
> that would fit nicely with density experiments
Water as a medium is technically possible but I'm still not sure how
could it fit in the UI. Maybe it could be a type of world. There are
plans to do an 'outer space' world (zero gravity, zero friction) and
maybe a moon world (low gravity, maybe zero friction). I think water
world could fit nicely as an option there. Should it be half empty or
half full? :-)
There is an example here on how water looks with the physics engine.
> how hard would it be to have a feature where mass is measured and / or
> displayed on the object?
Not technically hard. We've been thinking on also showing the velocity
vectors of bodies but again, the difficulty is how to integrate it
without complicating too much the UI or even if it's worth doing. If
we only have a simple list of materials and we could distinguish the
material of a body by color. How do you think we could benefit from
having a way to get a number that measures the the mass?
> On Sun, Aug 16, 2009 at 4:59 AM, Gary C Martin <gary at garycmartin.com> wrote:
>> Hi Bill,
>> Not sure if you wanted answers :-)
>> On 15 Aug 2009, at 02:51, Bill Kerr wrote:
>>> I might try these next week and see how they go:
>>> does altering the size of an object affect its drop time?
>>> does joining objects together (large and small) affect drop time?
>> 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!
>>> does altering the length of a pendulum affect its swing time?
>> 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).
>>> before doing the above say what you think will happen
>>> after doing the above say whether you think the physics program reflects
>>> real world behaviour
>>> (possibility of follow up real world experiments here)
>> "possibility of follow up real world experiments here" nice :-) +1
>> 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").
>>> design a catapult system to accurately hit
>>> (a) stationary distant target (b) moving target (c) close target
>>> build a complex or elegant building that doesn't fall down
>> 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 ;-)
>>> other ideas along these lines?
>> General miscellaneous tips:
>> - 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).
>> - 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.
>>> extra features I would like to see in physics:
>>> copy shapes
>> Not on our feature list, will have a think how practical this would be to
>> actually implement.
>>> move them while in setup mode
>> 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!).
>>> a timer
>> 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.
>> 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).
>>> I think it would be better if the polygon icon looked like an irregular
>>> shape rather than a regular hexagon
>> Have this feature request already, you should get it in the next release
>>> 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
>>> eg. make a tessellation in setup mode and then support it so it doesn't
>>> fall apart under gravity
>> Not planning on this, but will keep it on a possible feature list.
>> Thanks for all the great feedback so far!!
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