Physics problem

January 29, 2001 8:46 PM

Physics problem A "Discovery" program for kids at MSN.com explores the physics of skydiving, specifically the trajectory of an object dropped from a moving plane. Problem is, their demonstration animation looks completely phucked. More inside...
posted by Tubes (8 comments total)

Unless this is a quirk of processor speed or something, the ball "dropped" from their plane acts as if it was fired rearward from a cannon! I'm appalled that they'd foist this off as science...
posted by Tubes at 8:48 PM on January 29, 2001

Hm... The only possible explanation I can think of is that the person responsible has seen lots of movies where people jumping from a plane seem to "shoot" backwards, due to their terminal velocity being less than the planes forward speed...

But yeah, even the diagram of the problem has the trajectory of the ball flying out behind the plane... Weird.

Now, Tubes, I don't mean to pry, but how, exactly, did you *find* this?...

(The actual "mission" is here, btw.)
posted by whatnotever at 9:28 PM on January 29, 2001

I really doubt this is a processer speed thing. Since the slowness that mght affect the speed of the plane should also affect the "skydiver". What an awful, awful simulation. It's really too bad, since they're trying to teach something here, and are doing it so completely wrong. (and discovery.com's usually pretty good about this stuff).

All I can think is that somebody's math was off when figuring the apparent speed of the object vs. the actual speed of the animating sprite.

But how the Hell did that make it past even a cursory test pass? Yeesh.
posted by kokogiak at 10:17 PM on January 29, 2001

Actually, it looks like they were missing a minus sign somewhere in the simulation. I think the ball's backwards speed is equal to the plane's forward speed. I could be wrong here, and the lack of testing is still suspect, but I suspect the ignorance of physics isn't quite so deep as it first appears.
posted by grimmelm at 10:45 PM on January 29, 2001

Indeed, from reading the 'letter' that introduces the mission it's apparent that someone understands the correct physics, "He jumps out of the plane way before he is directly over the target!" So they had the right idea.

That it got online like this however is beyond belief.
posted by Reto at 12:01 AM on January 30, 2001

lol, they might have uploaded the wrong version by accident. have any of you emailed them to mention the problem? -- it won't get fixed otherwise.
posted by ookamaka at 12:22 AM on January 30, 2001

Now, Tubes, I don't mean to pry, but how, exactly, did you *find* this?...

Fair question. I followed a link from the MSN homepage. I think it mentioned skydiving so it caught my jumper's eye.

Confusing stuff like this can imprint a kid with misconceptions that hinder their understanding of basic physics.

I'll look for an e-mail address to complain to...

posted by Tubes at 11:09 AM on January 30, 2001

I e-mailed them and got this back.
Hi there,
It's very important to us to know what you think about our site. We are sorry that you had a bad experience, and we will look into the problem to see if we can fix it. Thanks for helping us make our site a better place for kids!
MSN Kids
posted by quirked at 7:54 AM on February 1, 2001