From: charlie@elektro.cmhnet.org (Charlie Smith)
Newsgroups: rec.motorcycles
Subject: Re: The vertical 1/4 mile
Date: 21 Dec 92 16:19:02 GMT
Organization: Why do you suspect that?

In article <1992Dec20.204056.20820@rd.hydro.on.ca> jlevine@rd.hydro.on.ca (Jody Levine) writes:
>In article <1h154nINNh3@agate.berkeley.edu> robinson@cogsci.Berkeley.EDU (Michael Robinson) writes:
>>In article <1992Dec19.203501@cs.wpi.edu> ravi@cs.wpi.edu writes:
>>>    hey! our own motoring vehicle isn't all that bad you know? i read
>>>    somewhere (was it the recent issue of rider?) that the zx-11 leaves
>>>    the space shuttle lagging way behind in the quarter mile!!!
>>
>>It seems to me that this is but a trivial variation on the recently 
>>concluded "accelerating down a cliff" thread.  The ZX-11 doesn't go 
>>anywhere straight up.
>>
>>To make a fair comparison, you'd have to put the Shuttle on rails, or 
>>the ZX-11 on a really powerful, 1/4-mile-high magnet.
>
>It's quite simple really.
>
>total acceleration of ZX-11 over 1/4 mile > total (acceleration of space
>shuttle - 9.8 m/s/s) over 1/4 mile. After all, that first bit that
>the shuttle does looks pretty slow. No matter. I'd like to try both. 
>
>I've        bike                      like       | Jody Levine  DoD #275 kV

It's a simple matter of applied physics, as it were.  The question was 
which vehicle accelerates faster over a 1/4 mile <?>

Of course, each vehicle operates in a different natural environment, 
one horizontal and one vertical; so some leveling of environments 
(no pun intended) is needed to make a meaningful comparison.  

What needs to be calculated for each vehicle is overall corrected 
acceleration from it's point of origin, taking into account the rate 
of change of distance moved away from that point of origin per unit 
of time and factoring in all the forces involved that influence that 
rate of acceleration.  The largest influencing force that I can think 
of in this regard is the force of gravity.

If the corrected acceleration of each vehicle is measured in G's, the 
situation can be seen pretty clearly.  The bike's acceleration is 
corrected by an "influencing force" factor of +(0*1G) since the bike is 
likewise corrected by an "influencing force" factor of +(1*1G) since the
shuttle is actually accelerating enough to overcome this influencing
force plus to accomplish movement away from it's point of origin.

My physics is too rusty at this point to write the complete formulae,
but the general form of the "influencing force" correction factor
should be *(x*1G) where 'x' is the sine of the angle away from
horizontal.  Might actually be cosine, I don't remember.

However, is seems intuitively obvious that the "corrected" acceleration
of the shuttle is much larger than that of the bike.

It would be interesting to apply these formulae to the previous problem
of whether a bike could accelerate down a slope faster than the same
bike could fall off a cliff.  Done properly, this should provide an answer
to both problems once and for all.  Ha!


Charlie Smith   charlie@elektro.cmhnet.org  csmith@dsac.dla.mil  whois ces10
MOA# 52888, RA# 15633, DoD# 0709, AMA# 574722, Buckey Beemers 411, BK Ohio V
BMW K1100-LT, R69S, R27 and other even less worthwhile [ 2 | 3 ] wheel stuff

                 {    physics major, years ago    }
Newsgroups: rec.motorcycles