Math / Science

The Math / Science topic primarily includes discussions of mathematics, physics, statistics and economic analysis, but also biology, chemistry and other sciences.

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I thought of using those 2 litre juice plastic bottles (like the Marigold ones) to hold gasoline as there's offer for gasoline currently.   But there are links in the Net that gasoline will dissolve plastic : is this true?

What are the cheapest containers to hold gasoline/petrol?
What does it mean to be "Always On"?
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Suppose I need quantity Q grams of honey, and I can buy packs of honey in either 340g or 454g pack sizes. These packs cost 1.79 and 2.19 respectively (cost per kilo is therefore 5.26 and 4.82 respectively)

I buy m packs of 340g and n packs of 454g

Question: express m & n in terms of Q in order to minimise cost for any given Q.

I believe this is a solution:

But this maybe overbaking it (the least common multiple of 340 and 454 is 77180)

Wandering if I'm missing a shortcut somewhere.

I am drawing rectangles using 4 points. Resizing is done with mouse dragging of one point. Resizing is simple if rectangle is not rotated, but how to calculate points if it is. Idea is to drag one point and appropriately calculate two neighboring points of the rectangle while the opposite is always still. It is mathematical problem and I am a little short how to do it. I'am using C++ builder GDI. Any idea?
Dear experts,

In the attached image I have the Principal solution for positive and negative sin theta. The image shows how the negative theta values are reflected as positive alpha values.

Can someone please guide me to an article in public domain for equivalent workings of Cot, cosecant and secant theta.

Thank you
I'm running SQL Server 2012.. .wondering if anyone has seen any procedures of functions for doing Monte Carlo simulations on financial data such as the stock markets.

Seems there may be a function in 2016, but we're not there yet.

Anyone have experience in this area?
Thank you!

(I'm also using Coldfusion if there is something there too)

During the past 10 years, the level of demand for a company's product has increased from 1,150 units per day to 2,150 units per day. What was the average annual compound growth rate over this period? Show the solution.

1.8695 = (1+g)^10
Growth Rate=10%
What are typical application in the life science industry ?

Bio reactor? how does a bio reactor work?
Car dealer told me 15" saves more fuel & is more suited for Sienta hybrid  (& Airwave)
while 16" is more suited for Toyota C-HR.

I like 16" so that my bumper is not too low & often get scratched when reverse-parking
or head-in near high pavements (have seen pavements of 9-10" higher than parking

Is this true that 15" saves more fuel?

which one can accelerate faster or no diff?

which one is more stable ?  I tend to think lower centre of gravity makes
an object less likely to overturn
The future of ergonomics! Probably.

To nerd it up for us: Imagine a keyboard made to exactly match the way your hand moves.
How to calculate ''32% Undergraduate Grade Point Average?
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Hello again,

We forgot to ask you a question about prime numbers.

We are indeed releasing a number primality check tool for which there is no actual size limit beyond the one we have imposed for material resource issues.

However, it is often mentioned the existence of ILLEGAL prime numbers and we do not quite understand the meaning of being able to define a number, which ever it may be, illegal.

However, given the nature of our tool which has no processing limit, we do not wish to have any problem with the authorities.

What is your opinion on the issue, do you think we expose ourselves to any risk by releasing such a tool?

Looking forward to hearing from you.

Best regards,


P.S. In attachment you will find a text file contains the 3 previous and the 3 next numbers following the first illegal known one that contains 1401 digits.
twitter sentiment analysis using Matlab   , kindly tell me whenever i import MaxentTagger class , i generate error that *. is must fot import statement..

Even i put *. but still MaxentTagger methods are not imoported in my program.....    

function result = PosTaggerM(str)
      import edu.stanford.nlp.tagger.maxent.MaxentTagger.*;

      % This initialization is expensive.
        % It is better to create the tagger once and then reuse it.
      tagger = MaxentTagger('C:/Program Files/MATLAB/R2017a/bin/english-left3words-distsim.tagger');
      result = java.util.ArrayList();
      sentences = MaxentTagger.tokenizeText(StringReader(str));
      for ii = 1:size(sentences)
            tSentence = tagger.tagSentence(sentences.get(ii-1));

ERROR GENERATED on RUN     Undefined function or variable 'MaxentTagger'.

Error in PosTaggerM (line 40)
      tagger = MaxentTagger('C:/Program Files/MATLAB/R2017a/bin/english-left3words-distsim.tagger');
I watch and have looked at information to get me  as far as I am now all I need before I can run is to target it I know its com  but have no I idea on the prefix
I am trying to find the term used in chemistry to describe the tendency of a 2-way chemical reaction to prefer one chemical combination over the other, such as in Keto-Enol in organic chemistry. I can only recall using the term affinity, but that is not precisely what I am looking for.
I have  a table
   TransType [Deposit/Withdrawal/Interest]

I would like to be able to calculate the Time Weighted Return for this table (here is the formula )

any help on how to do that in Access would really be appreciated


This is a follow-up question to a previous thread located here:

Auto-fill a cell's color based on numeric RGB values and vice versa in Excel

In that thread, the solution (by Ejgil Hedegaard) includes an attached Excel file in which the fill color of a particular cell, automatically changes in response to entering various values in three other cells labeled R (red), G (green), & B (blue).

This functionality is tremendously useful for me (and I suspect will be for others) because it enables you to instantly view the new color resulting from changes in any of the RGB parameters (ie without the necessity of the four clicks typically required to obtain that information):

        Home > Fill Color > More Colors > Custom

(The file also includes a chart for quickly converting from RGB decimal to RGB hex and vice versa.)

Additionally, the solution to the thread contains the formula for calculating Excel's color code:

        ExcelColor = R + G *256 + B *256^2

For example:

        Red = 204
        Green = 102
        Blue = 255

is calculated as follows:

        ExcelColor = 204 + (102*256) + (255*256^2)
        ExcelColor = 16737996

It also displays the following for reversing the process (ie :

        R = C Mod 256
        G = C \ 256 Mod 256
        B = C \ 256^2 Mod 256

Are these three formulas math or code and what is the purpose of the backslash?
One of my favorite things to do is play games. Seriously, I built an entire table from scratch for nothing other then to play and store my many games.

I also know new parents and veteran parents who are looking for more fun to have with their young children.

So when Google Announced that the Assistant, Home and Mini would be able to play games…I had to investigate.

Google breaks it down into these categories:

Learn Together
Have fun with your family and little ones with quizzes or learn things together.

Talk like a Chef (Hey Google, Play Talk like a Chef)
CK-12 EDU Trivia (Hey Google, talk to CK-12)
Space Trivia (Hey Google, play Space Trivia) Quiz (Hey Google, talk to
Homework Help (Hey Google, help me with my homework)
National Geographic Bee (Hey Google, talk to National Geographic Bee)
Trivia Showdown (Hey Google, talk to Trivia Showdown)
Math Showdown (Hey Google, talk to Math Showdown)
Everyday Hero (Hey Google, Talk to Everyday Heroes)
Talk Like an Astronaut (Hey Google, play Talk Like an Astronaut)
Sporcle Junior (Hey Google, talk to Sporcle Junior)
Planet Quiz (Hey Google, talk to Planet Quiz)
Quizziz (Hey Google, talk to Quizzizz Student)
Animal Trivia (Hey Google, play Animal Trivia)
Play Together
Have some digital fun with the family with these games, trivia and more!

Musical Chairs (Hey Google, play Musical Chairs)
Which DC Superhero are you most like? (Hey Google, what’s my Justice League superhero?)
LVL 25

Expert Comment

by:Brian B
IMHO, this might be good information for an article if you add a little more description.

I'd like to take a list of intervals defined by pairs of numbers, eg

and convert this into a consolidated list counting any overlapping intervals as one, so the above example would give:

See attached drawing that illustrates this.

I want to do this with array/matrix operations, if possible, so I can implement in google sheets without coding.

Aerodynamic noise is the cause of the majority of the noise produced by helicopters. The inordinate amount of noise helicopters produce is a major problem in the both a military and civilian setting. To remedy this problem the use of an aerogel coating over the airfoils of a helicopter was examined.
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I got the positive number multiplication right and I can kinda do negative numbers . but I cant do both at the same time
my try code
        STA A
        STA B
        LDA A
        BRZ END
        LDA B
        BRZ END
        LDA NUM
        SUB B
        BRP CHANGE
        SUB B
        STA B
        LDA NUM
        SUB A
        STA A
        BRZ END
        SUB ONE
        STA B
        LDA P
        ADD A
        STA P
        BRA LOOP
        SUB P
        STA P
A       DAT
B       DAT
P       DAT 0
ONE     DAT 1
NUM     DAT 0
Can you guys please suggest me some good free web sites for the preparation of mcat exam?

I remember from my days of teaching school science that we used to demagnetize nails by hitting them with a hammer and magnetize them by stroking with a magnet until the atoms aligned in the same direction.

My friend was showing me an app on his phone where the accelerometer sometimes fails and you are advised to reset it by moving the phone in a figure of 8. I was curious why the figure of 8. I'll break my question into 2 separate parts as that's what my feeble brain needs :)  If you are kind enough to respond to this, please can you address the sub-questions in turn. For simplicity I am assuming the accelerometer is just a magnet

a) When atoms reorient themselves to be magnetized do they turn clockwise, anticlockwise or both directions (just curious)?
b) How does the figure of 8 movement reset a magnet? The electromagnetic field lines on either side of a bar magnet do look like a figure of 8 on its side. My days of knowing electromagnetism are long gone but is it a fair simplification to say by following the magnetic field lines that should be around your phone if its magnet were 'working,' you actually realign the atoms in the magnet. If that is the case I'm not sure how this works as it is not as obvious as the notion of  stroking a nail with a magnet to realign the atoms. If my simplification is correct I do not need to know how this works as that probably requires a physics degree so all I would ask is that confirm or disconfirm my suggestion (unless …
It's my math problem I'm struck
This could be an easy question and in fact, this is simple. But just wondering what's the proper algorithm for lucky draw chances?

Let's say in every new deposit amount of X get a no of chances of Y. Providing X = $1000, Y = 1

If there's a customer A credited $10000, he got 10 chances in this month.
If there's a customer B credited $2000, he got 2 chances in this month.
If there's a customer C credited $100, he got 0 chances in this month.
If there's a customer D credited $3500, he got 3 chances in this month.

By end of this month, how do I use a proper algorithm to pick a lucky draw winner? That's to pick a winner among this 15 chances.

One of the approaches is to create multiple chances in a temp table, and then random a position to pick the winner. But my question is what if the total no of chances is a very big number? Will the process of populating this temp table become slow?

Thank you.
A workshop table has an equilateral triangular top each side 900mm the legs are on the three corners . A load of 500N is placed on the table at point distant 325mm from one leg and 625mm from another . What is the load on each of the three legs

Math / Science

The Math / Science topic primarily includes discussions of mathematics, physics, statistics and economic analysis, but also biology, chemistry and other sciences.