Monday Quiz

[velo90 0]

Can anyone see a relationship between the Saturday Quiz and the Sunday Quiz ?

[kallend 1,647]

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Can anyone see a relationship between the Saturday Quiz and the Sunday Quiz ?

Yes.

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The only sure way to survive a canopy collision is not to have one.

[rehmwa 2]

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Yes.

Short, elegant and to the point. of course

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Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

[velo90 0]

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Can anyone see a relationship between the Saturday Quiz and the Sunday Quiz ?

Yes.

Good.

Are we agreed that if the winds at exit altitude (13,000 ft) are say 50 kts, and they drop to 0 kts at 5000 ft. you cannot calculate exit seperation based purely on airspeed?
While the balloon example shows that ground speed counts for jack shit when it comes to seperation, the space ball example shows that air speed is not the answer either.
I just hope that people will take the time to figure out what is going on.

Dave

[winsor 187]

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Can anyone see a relationship between the Saturday Quiz and the Sunday Quiz ?

Yes.

Good.

Are we agreed that if the winds at exit altitude (13,000 ft) are say 50 kts, and they drop to 0 kts at 5000 ft. you cannot calculate exit seperation based purely on airspeed?
While the balloon example shows that ground speed counts for jack shit when it comes to seperation, the space ball example shows that air speed is not the answer either.
I just hope that people will take the time to figure out what is going on.

Dave

I hope you include yourself among the people who need to take the time to figure out what is going on.

We are not agreed that you cannot calculate exit separation based purely on airspeed, so long as you can calculate the exit speed relative to the airmass at opening altitude.

If all you have is exit airspeed and groundspeed, you can still make a good estimate of an appropriate exit interval that will ensure horizontal separation between exit and opening altitude.

A clear understanding of the kinematics involved is pivotal, but apparently elusive.


Blue skies,

Winsor

[velo90 0]

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I hope you include yourself among the people who need to take the time to figure out what is going on.

I have indeed spent a lot of time trying to figure out what is going on.

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If all you have is exit airspeed and groundspeed, you can still make a good estimate of an appropriate exit interval that will ensure horizontal separation between exit and opening altitude.

Exactly! All I wanted to say was air speed at exit time (edit: I mean the air speed of the aircraft) was not the sole parameter in calculating exit interval. And thankfully you brought ground speed into the discussion.

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A clear understanding of the kinematics involved is pivotal

How many skydivers do you know that have this understanding?

Blue ones
Dave

[rehmwa 2]

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How many skydivers do you know that have this understanding?

7

BTW (just to be a smart ass as I know Winsor understands this - from one of the quizzes, space balls don't have an opening altitude, which means descent rate is constant, thus the different wind speed layers don't affect separation.....it's all about how much time each group spends in each of different wind layers - or better yet some integral of that, but that's just a little too much for the weekend)

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Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

[winsor 187]

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A clear understanding of the kinematics involved is pivotal

How many skydivers do you know that have this understanding?

[kallend 1,647]

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A clear understanding of the kinematics involved is pivotal

How many skydivers do you know that have this understanding?

Actually, rather a few - the sport is rife with techies.

In most technical degree programs Physics 101 or its equivalent is a Freshman course. Anybody with an Bachelor of Science degree should have covered this material at some time early in their educational curriculum (if not in High School).

I suppose I learned this stuff enough decades ago that I really don't remember what it's like not to understand it, and don't have much patience for people who demonstrate ignorance of things that I assume are simple.

Dr. Ralph Heller, a professor at my alma mater, was reputed to have once told a Freshman class "I've been teaching this subject for thirty five years - you should understand it by now!"

His students weren't amused, but I know how he felt.


Blue skies,

Winsor

[rehmwa 2]

Still think it's more accounting than physics.

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Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

[kallend 1,647]

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Still think it's more accounting than physics.

Arthur Anderson showed that accounting doesn't always give the right answer. I'll trust physics.

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The only sure way to survive a canopy collision is not to have one.

[rehmwa 2]

You're on a roll today. I'm hoping to make it to a 4-way meet in the chicago area this summer. I will buy the first round.

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Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

[kallend 1,647]

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You're on a roll today. I'm hoping to make it to a 4-way meet in the chicago area this summer. I will buy the first round.

Deal. Were you at Couch Freaks last year?

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The only sure way to survive a canopy collision is not to have one.