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Conference rusure::math

Title:	Mathematics at DEC

Moderator:	RUSURE::EDP

Created:	Mon Feb 03 1986
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	2083
Total number of notes:	14613

1900.0. "Calculating Altitude - I forgot {blush}" by GLDOA::RBROWN (Yep, its me again ...) Mon Oct 03 1994 08:31

Hi !!

	I just found an old treasure of mine.  I used to launch Estes 
rockets as a kid, and found them when I visited my folk's home.  Along with
a number of older rockers, engines (see previous note), and odds and ends,
I found an old slide rule in the bottom of the box.

	Now that I have kids of my own, I like to make learning experiences
out of the fun we have together.  I use to use the slide to compute the
height that the rocket.  I have, however, forgotten my trig, and how to
compute the height.  Can anyone remind me ?


			 d	b
			 |     /
			 |   /
			 |  /
			 | /
			 |/
			 a----------------c

		a = launch site
		b = angle (in degrees), where the rocket turned
		c = distance in feet where the rocker landed
		d = Heigth ??

	I seem to recall the need for a trig table, and looking up the value
of something, (tangent perhaps ?).

T.R	Title	User	Personal Name	Date	Lines
1900.1	This oughta do it	VMSDEV::HALLYB	Fish have no concept of fire	`Mon Oct 03 1994 09:15`	18
	d b \| /\| \| / \| \| / \| \| / \| \|/ \| a------+------c e Let e = (a+c)/2, the distance from launch to the epiapogee :-) then tan(a) = b/e, of course this is not "allowing for the wind". or b = e�tan(a) But it's a lot more fun to solve this from the equation of a parabola! John
1900.2	Thanks !	USOPS::RBROWN	Yep, its me again ...	`Mon Oct 03 1994 10:06`	7
	John, Thanks ! And my son thanks you. But he doesn't know how much yet, no trig, no launch the rocket we just built. The carrots are different in the 90's ... Randy
1900.3		WRKSYS::BRANDENBERG		`Wed Oct 05 1994 20:47`	7
	> I just found an old treasure of mine. I used to launch Estes >rockets as a kid, and found them when I visited my folk's home. Found them? When I was a kid, all of mine carried explosive payloads... If they went up, they never came back down... :-) Of course, I did have a large collection of unused Estes parachutes..
1900.4		HANNAH::OSMAN	see HANNAH::IGLOO$:[OSMAN]ERIC.VT240	`Fri Oct 07 1994 10:11`	17
	>> I just found an old treasure of mine. I used to launch Estes >>rockets as a kid, and found them when I visited my folk's home. > >Found them? When I was a kid, all of mine carried explosive payloads... >If they went up, they never came back down... :-) Of course, I did have >a large collection of unused Estes parachutes.. Your response is assuming that "and found them when I visited" refers to finding ones that had been launched. I assumed the found ones were ones that were never launched. Anyway, regarding yours that went up and never came back down, wouldn't that mean it reached escape velocity ? (the value of which escapes me) /Eric
1900.5		ULURU::GARSON	achtentachtig kacheltjes	`Sat Oct 08 1994 03:20`	7
	re .4 Escape velocity is 10.something km/sec (upwards). I don't think so somehow unless this guy works for NASA (-:. I suppose they "didn't come down" because the payload blew the rocket into little bits.
1900.6		WRKSYS::BRANDENBERG		`Tue Oct 11 1994 14:29`	6
	> I suppose they "didn't come down" because the payload blew the rocket into > little bits. In a most satisfying and infamy-producing manner... :-)
1900.7	Mine went up, and went up again ...	GLDOA::RBROWN	Yep, its me again ...	`Tue Oct 18 1994 08:35`	10
	OK OK ... I found rockets that went up, many times in fact, but I used the parachutes. I launched the rockets in a large park, but the park was located inside a subdivision. I was careful to make that safety precautions were taken. I didn't want to hurt anyone, or lose a rocket. In "them old days", you had to send directly to Estes to get them. Today you drive to KMART .... {sigh} Anyway, thanks for the help !