Readers' Feedback

Mathematics

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Generated : 26th May 2024


006

Jon Wells

Jon3sticks@aol.com

Your page showed me a bunch of formulas, but not the one to help me calculate this matter:

At Disney World, there is an elevator which evidently simulates free fall. It descends accelerating at 32 ft/ses/sec for thirteen stories (let's say 130 ft?). Assuming a negative acceleration (so the passengers won't be squashed) equal to the positive acceleration of the fall, how many seconds of free fall would an occupant experience.

Answers, formulas, hints?

Thanks!

KryssTal Reply: The formula you want is d = (1/2) g t^2

where d is the distance, g the acceleration and t the time (seconds). Rearrange to get

t = square root (2 d / g)

Hope that helps.

It does help! Just the formula I was looking for.


005

Jason Noel

islandscout@hotmail.com

Kryss, am having trouble with a problem, and hoped you could help me out with it. (7Q + 6P)^21 If you have time, I would greatly appreciate the help!

Thanks, Jason. P.S. found you while browsing HOTBOT

KryssTal Reply: Hello there. What do you want to do with this expression? Expand it? If so you will find a way of expanding expressions like this on my web page below.

binomial.html


004

Prof. S.N.Ghosh

sng@civil.iitkgp.ernet.in

Dear Mr.Krysstal,

The formula given by you is named simply as the Qudratic formula,but the actual formula was calculated by Pandit Shreedharacharya. It is known as Shreedharacharyas formula and I think that you should give the credit when it is due. I would greatly apreciate if you write the name as Shreedharacharyas formula.

You can contact me at archishman@hotmail.com Waiting for an answer shortly, yours sincerely,

Archishman.


003

Jessica Brissette

Brissjes@coleman.k12.wi.us

Do you by any chance know the formula to find a square root with out a calculator??

KryssTal Reply: Check out my page below under Binomial Theorem.


002

G. L. Honaker, Jr

sci-tchr@3wave.com
Prime Curios! http://www.utm.edu/research/primes/curios/

Wow ... I'm impressed with your work. It's very attractive and there seems to be all sorts of related topics of interest here. Bookmarked!

KryssTal Reply: Thank you very much.


001

Elyssa

LyssaGrl2000@aol.com

Dear whomever it may concern,

I am a ninth grader writing a report on Pascal's Triangle, so far your website has helped me very much. When I came across nCr I became confuse to what C stands for. If you could possibly tell me I would appreciate it.

Also if you have any other information or hints to what books I should look at or what websites I should visit I would appreciate it if you would inform me.

Thank you very much

KryssTal Reply: Hello Elyssa. Thank you for reading my page. I'm afraid I don't know what a "ninth grader" is because in England we don't use grades.

The C in the formula stands for COMBINATIONS. There is a similar formula with a P in it (for PERMUTATIONS).

Try looking in the Fun Science Web Ring. For a list of sites click the link below.

http://www.webring.org/cgi-bin/webring?ring=funscience;list

Good luck with your project. Tonight I have added a new mathematics essay to my web site. It is about numbers and can be found here:

http://www.krysstal.com/numbers.html

I discovered this while writing my report . Tell me if this has already been discovered:

As I began to learn about the many patterns in Pascal's triangle I began to explore. While exploring I found a different pattern. I have not come across it while doing my research, yet it may have already been discovered. I have discovered that when you make an interior triangle, where two of the numbers are adjacent to the exterior number ones, much like the one in the figure the two numbers adjacent to the exterior when multiplied equal the third number multiplied by two.

a x b = 2c

5 x 4 = 2 x 10

20 = 20

KryssTal Reply: Very interesting!

This looks like a general rule. You are multiplying nC1 by (n-1)C1 in your first numbers. This gives n and n-1 respectively.

This gives n(n-1).

If you take the third number and multiply it by 2 you get:

2 X nC2 = 2n! / (n-2)!2! = n(n-1)

So yes, you have discovered something new - be proud!


© 2024, KryssTal

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