cancel
Showing results for
Did you mean:
cancel
Showing results for
Did you mean:

## Neat trick

SOLVED
Highlighted

From the first post in the challenge thread:

*The winner will be chosen based on time of response, accuracy of solution, and best use of Mathcad to derive the answer.

Show me where it says that the trajectory will be based of the crater floor!

The contest was very poorly run, that response is ridiculous. I'm guessing that after waiting two weeks to see if more than 2 people participated in your "Challenge" you picked the person who would cost you the least in shipping.

You added a new rule regarding where the height was to be zeroed to back up your decision and stuck to it.

I was never offered a t-shirt and sure don't want one now.

Highlighted

We'll work harder to be more clear in defining the variables and assumptions. Thank you for pointing out this flaw in the contest. The offer for a t-shirt is still valid. I apologize for assuming you no longer wanted one.

Highlighted

## Re: Neat trick

All I want is confirmation from my last question from the other thread, that all of the below is trumped by having the "correct" (but yet unstated in the rules) zero point on the trajectory:

"You have nothing to indicate that on your diagram and during the presentation, I believe that it was announced that "h = 75m". Your diagram also shows a two ended arrow which indicates that h is only a scalar, does not have direction and does not indicate the y origin (by pointing away from it).

My solution was in ten minutes before Chris’.

After solving the equation for vertical motion (without setting it equal to some time variable), he copied both solutions. He incorrectly copied one solution and came up with 2.019s, which has now had no reason to be ignored.

He then cut and pasted again (to only three decimal points) one of the two times into a formula for horizontal displacement – not using mathcad’s ability to update if there were any changes before the point and rounding this time value off. He took the unneeded step of calculating and displaying the time until impact.

He then solved the vertical and horizontal components by plotting the two with discrete points at ½ second intervals, only up to slightly more than the time he calculated previously. He then plotted the two vectors (horizontal vs time and vertical vs time) against each other. This seems very sloppy, not robust, and doesn’t use mathcad’s ability to pass along and update information.

As for the horizontal distance, (Chris 2641m, Me 2609m), he used 1.6m/s^2 instead of the more accurate (from NASA) 1.62m/s^2 (see below).

And the ten minutes difference doesn't seem like much, but look at it like this: The information was provided at each of the sessions at 45 minutes past the hour. I submutted my solution at 1:49 pm. The other solution was submitted at 1:59 pm. So mine was in 4 minutes after the last clue was given and the next answer took 14 minutes after the last clue.

You finally offered a t-shirt in a private message saying that you didn't think I was interested because of my comments in the other thread. Those comments were posted on November 22nd. The event was Setemper 8th. Where was the offer in that length of time?

Highlighted

## Re: Neat trick

Dan,

If you read the previous post in this thread, I pointed out the difference as I see them and recieved no response. I stated that the time difference was not the only issue, but also differences in accuracy and the use of mathcad.

I did not recieve an offer for a t-shirt before I posted my comments 10 weeks after the event. I appologize if I appear frustrated, I did not mean to abuse anyone in this community. I am just looking for confirmation that the points I made were considered and that was the reason for the judges decision.

Thank you

Highlighted

## Re: Neat trick

Tom, your points were valid and were considered during the judging process. It even led us to incorporate more [clear] assumptions to shape future challenges so there will be little chances of ambiguity when considering variables.

-Dan

Highlighted

## Re: Neat trick

Thank you Dan for providing some insight into the judging process and the weight certain factors have. Unfortunately this has not changed my opinion of how that contest was ran

I will have to think long and hard about investing any more time into any future contests/events here.

Good luck in the future.

Highlighted

## Re: Neat trick

The thread is locked, so I agree that it shouldn't show up in the latest activity list.

Mike

Announcements