need help finding a formula for my calc - Hewlett Packard

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  1. need help finding a formula for my calc

    Let's say you have a ball (shpere) that weighs 10 pounds the
    material is brass which have a density of .305 cubic feet. this is all
    the information I have. How can I find the diameter of the ball. I
    would like to program the formula on my hp50. thank in advance


  2. Re: need help finding a formula for my calc

    On Mar 24, 6:03 am, gotu...@aol.com wrote:
    > Let's say you have a ball (shpere) that weighs 10 pounds the
    > material is brass which have a density of .305 cubic feet. this is all
    > the information I have. How can I find the diameter of the ball. I
    > would like to program the formula on my hp50. thank in advance


    Sounds like homework.

    Also, density is weight per volume (e.g., pounds per cubic feet).

    Also^2, what is the volume of a sphere as a function of its radius?


  3. Re: need help finding a formula for my calc


    "mjc" wrote in message
    news:1174751060.339963.145670@e1g2000hsg.googlegro ups.com...
    > On Mar 24, 6:03 am, gotu...@aol.com wrote:
    >> Let's say you have a ball (shpere) that weighs 10 pounds the
    >> material is brass which have a density of .305 cubic feet. this is all
    >> the information I have. How can I find the diameter of the ball. I
    >> would like to program the formula on my hp50. thank in advance

    >
    > Sounds like homework.
    >
    > Also, density is weight per volume (e.g., pounds per cubic feet).
    >
    > Also^2, what is the volume of a sphere as a function of its radius?
    >


    Hardly homework, a very common problem we all wrestle with. Lots of people
    have brass balls. Some, like myself, have steel balls. Some people have no
    balls at all but they are good at calculating the size of someone else's
    balls.



  4. Re: need help finding a formula for my calc

    On Mar 24, 12:12 pm, "Revolvr" wrote:
    > "mjc" wrote in message
    >
    > news:1174751060.339963.145670@e1g2000hsg.googlegro ups.com...
    >
    > > On Mar 24, 6:03 am, gotu...@aol.com wrote:
    > >> Let's say you have a ball (shpere) that weighs 10 pounds the
    > >> material is brass which have a density of .305 cubic feet. this is all
    > >> the information I have. How can I find the diameter of the ball. I
    > >> would like to program the formula on my hp50. thank in advance

    >
    > > Sounds like homework.

    >
    > > Also, density is weight per volume (e.g., pounds per cubic feet).

    >
    > > Also^2, what is the volume of a sphere as a function of its radius?

    >
    > Hardly homework, a very common problem we all wrestle with. Lots of people
    > have brass balls. Some, like myself, have steel balls. Some people have no
    > balls at all but they are good at calculating the size of someone else's
    > balls.


    Sound so gay.

    Anyway,

    Since you managed to find this site, hopefully my assumption that you
    Googled "Volume of a Sphere" was done or you already know the formula.

    The question is how to best do this with the calculator. I would enter
    NUM.SLV (right shift 7), and take option 1 (Solve Equation), enter the
    equation you have (adjusting for and replacing the radius with the
    diameter or just get the radius and multiply by 2). Simply enter the
    value you have into the appropriate field, move cursor to the other
    value and solve for that value.

    The nice thing is you can save your equation. When you get out of the
    screen, the equation you used is saved under the name EQ. Using the
    filer, rename it to something you'll remember. Next time you use
    NUM.SLV, select CHOOSE and select your renamed equation.




  5. Re: need help finding a formula for my calc

    On Mar 24, 12:12 pm, "Revolvr" wrote:
    > "mjc" wrote in message
    >
    > news:1174751060.339963.145670@e1g2000hsg.googlegro ups.com...
    >
    > > On Mar 24, 6:03 am, gotu...@aol.com wrote:
    > >> Let's say you have a ball (shpere) that weighs 10 pounds the
    > >> material is brass which have a density of .305 cubic feet. this is all
    > >> the information I have. How can I find the diameter of the ball. I
    > >> would like to program the formula on my hp50. thank in advance

    >
    > > Sounds like homework.

    >
    > > Also, density is weight per volume (e.g., pounds per cubic feet).

    >
    > > Also^2, what is the volume of a sphere as a function of its radius?

    >
    > Hardly homework, a very common problem we all wrestle with. Lots of people
    > have brass balls. Some, like myself, have steel balls. Some people have no
    > balls at all but they are good at calculating the size of someone else's
    > balls.


    That sounds so gay.

    Anyway,

    Since you managed to find this site, hopefully my assumption that you
    Googled "Volume of a Sphere" was done or you already knew the formula.

    The question is how to best do this with the calculator. I would enter
    NUM.SLV (right shift 7), and take option 1 (Solve Equation), enter the
    equation you have (adjusting for and replacing the radius with the
    diameter or just get the radius and multiply by 2). Simply enter the
    value you have into the appropriate field, move cursor to the other
    value and solve for that value.

    The nice thing is you can save your equation. When you get out of the
    screen, the equation you used is saved under the name EQ. Using the
    filer, rename it to something you'll remember. Next time you use
    NUM.SLV, select CHOOSE and select your renamed equation.


  6. Re: need help finding a formula for my calc

    On Mar 24, 9:03 am, gotu...@aol.com wrote:
    > Let's say you have a ball (shpere) that weighs 10 pounds the
    > material is brass which have a density of .305 cubic feet. this is all
    > the information I have. How can I find the diameter of the ball. I
    > would like to program the formula on my hp50. thank in advance


    Since you managed to find this site, hopefully my assumption that you
    Googled "Volume of a Sphere" was done or you already knew the formula.

    The question is how to best do this with the calculator. I would enter
    NUM.SLV (right shift 7), and take option 1 (Solve Equation), enter the
    equation you have (adjusting for and replacing the radius with the
    diameter or just get the radius and multiply by 2). Simply enter the
    value you have into the appropriate field, move cursor to the other
    value and solve for that value.

    The nice thing is you can save your equation. When you get out of the
    screen, the equation you used is saved under the name EQ. Using the
    filer, rename it to something you'll remember. Next time you use
    NUM.SLV, select CHOOSE and select your renamed equation.


  7. Re: need help finding a formula for my calc

    On 24 Mar 2007 09:39:44 -0700, "bern" wrote:

    >On Mar 24, 9:03 am, gotu...@aol.com wrote:
    >> Let's say you have a ball (shpere) that weighs 10 pounds the
    >> material is brass which have a density of .305 cubic feet. this is all
    >> the information I have. How can I find the diameter of the ball. I
    >> would like to program the formula on my hp50. thank in advance

    >
    >Since you managed to find this site, hopefully my assumption that you
    >Googled "Volume of a Sphere" was done or you already knew the formula.
    >
    >The question is how to best do this with the calculator. I would enter
    >NUM.SLV (right shift 7), and take option 1 (Solve Equation), enter the
    >equation you have (adjusting for and replacing the radius with the
    >diameter or just get the radius and multiply by 2). Simply enter the
    >value you have into the appropriate field, move cursor to the other
    >value and solve for that value.
    >
    >The nice thing is you can save your equation. When you get out of the
    >screen, the equation you used is saved under the name EQ. Using the
    >filer, rename it to something you'll remember. Next time you use
    >NUM.SLV, select CHOOSE and select your renamed equation.



    Sounds like it might be a problem that could be solved using LaGrange
    Multipliesrs.
    See Mary Boas's Book "Mathematical Methods for the Physical
    Sciences". The 3rd edition is the latest edition out
    Harold A Climer
    University of Tennessee at Chattanooga
    Dept of Physics,Geology,& Astronomy
    Room 309 Grote Hall
    615 McCallie Ave
    Chattanooga TN 37403
    Harold-Climer@utc.edu

  8. Re: need help finding a formula for my calc

    On Mar 24, 6:26 pm, Harold A Climer wrote:
    > On 24 Mar 2007 09:39:44 -0700, "bern" wrote:
    >
    >
    >
    > >On Mar 24, 9:03 am, gotu...@aol.com wrote:
    > >> Let's say you have a ball (shpere) that weighs 10 pounds the
    > >> material is brass which have a density of .305 cubic feet. this is all
    > >> the information I have. How can I find the diameter of the ball. I
    > >> would like to program the formula on my hp50. thank in advance

    >
    > >Since you managed to find this site, hopefully my assumption that you
    > >Googled "Volume of a Sphere" was done or you already knew the formula.

    >
    > >The question is how to best do this with the calculator. I would enter
    > >NUM.SLV (right shift 7), and take option 1 (Solve Equation), enter the
    > >equation you have (adjusting for and replacing the radius with the
    > >diameter or just get the radius and multiply by 2). Simply enter the
    > >value you have into the appropriate field, move cursor to the other
    > >value and solve for that value.

    >
    > >The nice thing is you can save your equation. When you get out of the
    > >screen, the equation you used is saved under the name EQ. Using the
    > >filer, rename it to something you'll remember. Next time you use
    > >NUM.SLV, select CHOOSE and select your renamed equation.

    >
    > Sounds like it might be a problem that could be solved using LaGrange
    > Multipliesrs.
    > See Mary Boas's Book "Mathematical Methods for the Physical
    > Sciences". The 3rd edition is the latest edition out
    > Harold A Climer
    > University of Tennessee at Chattanooga
    > Dept of Physics,Geology,& Astronomy
    > Room 309 Grote Hall
    > 615 McCallie Ave
    > Chattanooga TN 37403
    > Harold-Cli...@utc.edu


    Which reminds that the density of brass varies but a good number is
    8400kg/m^3. The units (right shift 6) menu is nice for converting kg
    to pounds and m^3 to ft^3. This calculator really is a masterpiece.
    Just need to get used to it.


  9. Re: need help finding a formula for my calc

    On Mar 24, 6:26 pm, Harold A Climer wrote:
    > On 24 Mar 2007 09:39:44 -0700, "bern" wrote:
    >
    >
    >
    > >On Mar 24, 9:03 am, gotu...@aol.com wrote:
    > >> Let's say you have a ball (shpere) that weighs 10 pounds the
    > >> material is brass which have a density of .305 cubic feet. this is all
    > >> the information I have. How can I find the diameter of the ball. I
    > >> would like to program the formula on my hp50. thank in advance

    >
    > >Since you managed to find this site, hopefully my assumption that you
    > >Googled "Volume of a Sphere" was done or you already knew the formula.

    >
    > >The question is how to best do this with the calculator. I would enter
    > >NUM.SLV (right shift 7), and take option 1 (Solve Equation), enter the
    > >equation you have (adjusting for and replacing the radius with the
    > >diameter or just get the radius and multiply by 2). Simply enter the
    > >value you have into the appropriate field, move cursor to the other
    > >value and solve for that value.

    >
    > >The nice thing is you can save your equation. When you get out of the
    > >screen, the equation you used is saved under the name EQ. Using the
    > >filer, rename it to something you'll remember. Next time you use
    > >NUM.SLV, select CHOOSE and select your renamed equation.

    >
    > Sounds like it might be a problem that could be solved using LaGrange
    > Multipliesrs.
    > See Mary Boas's Book "Mathematical Methods for the Physical
    > Sciences". The 3rd edition is the latest edition out
    > Harold A Climer
    > University of Tennessee at Chattanooga
    > Dept of Physics,Geology,& Astronomy
    > Room 309 Grote Hall
    > 615 McCallie Ave
    > Chattanooga TN 37403
    > Harold-Cli...@utc.edu


    Which reminds that the density of brass varies but a good number is
    8400kg/m^3. The units (right shift 6) menu is nice for converting kg
    to pounds and m^3 to ft^3. This calculator really is a masterpiece.
    Just need to get used to it.


  10. Re: need help finding a formula for my calc

    >> How can I find the diameter of the ball.

    > Sounds like it might be a problem that could be solved using LaGrange
    > Multipliesrs.


    > How can I find the diameter of the ball.


    I think we're making this way too complex. All he needs is the volume
    formula.

    Unfortunately, he does not mention how many dimensions are involved.
    The volume of an n-dimensional sphere is given to be:

    V_n = (2*pi^(n/2)*R^n)/(n*Gamma(n/2))

    This provides opportunity to use your calculator's GAMMA function: LS-
    MATH, SPECIAL FUNCTIONS, GAMMA.

    Don't forget to double the radius to find the diameter.

    -wes


  11. Re: need help finding a formula for my calc

    On Mar 25, 3:58 am, "Wes" wrote:
    > >> How can I find the diameter of the ball.

    > > Sounds like it might be a problem that could be solved using LaGrange
    > > Multipliesrs.
    > > How can I find the diameter of the ball.

    >
    > I think we're making this way too complex. All he needs is the volume
    > formula.
    >
    > Unfortunately, he does not mention how many dimensions are involved.
    > The volume of an n-dimensional sphere is given to be:
    >
    > V_n = (2*pi^(n/2)*R^n)/(n*Gamma(n/2))
    >
    > This provides opportunity to use your calculator's GAMMA function: LS-
    > MATH, SPECIAL FUNCTIONS, GAMMA.
    >
    > Don't forget to double the radius to find the diameter.
    >
    > -wes


    Boy, we are sure having fun today!

    Are we in Euclidean space? As the saying goes, "Hyperbolic balls are
    better than no balls at all!".


  12. Re: need help finding a formula for my calc

    The other fellows on this list seem to have been having a lot of fun,
    but allow me to gently remind them: you were not always as
    knowledgeable as you are now. Here's a response a little more in line
    with the questioner's apparent level of experience.
    1. You know the formula for the volume of a sphere, I hope. If not,
    your first task is to look it up.
    So you will have a formula that looks something like
    V = 17 R^4
    where the "17" is a constant you will have discovered (it involves pi,
    which is available on the calculator as a constant -- see the SPC key)
    and the "^4" means "use the y^x key to raise the radius R to the power
    4". By the way, the actual power is not 4. That's one of the things
    you're supposed to look up.
    You'll also need to be aware that the formula you find will almost
    certainly be in terms of the radius, not the diameter D. But you know
    the relation between the diameter and the radius. So re-write the
    formula by substituting for R its definition in terms of the diameter
    D. Let's just pretend that you found D = 3 R below.
    2. Likewise, you probably know that given the "density" of a material,
    i.e. the weight (really, the mass, but this distinction may be yet
    ahead of your educational curve) per volume, you can calculate the
    weight via the formula
    W = K V
    for weight as a function of densityK and volume.
    You will need to find the density of brass. Again, it's on the Web. I
    strongly
    3. Solve the above two formulas. Remember algebra rules: anything you
    do to one side you do to the other. And also remember that you can
    raise things to fractional powers. For the example I gave, you would
    have
    W = D * 17 * (D/3)^4 (it's "3" because of what we are pretending
    from point 1 above, but you should use the correct number there)
    You isolate the R^4 on one side and then raise both sides to the power
    1/4. Remembering that raising a^b to the power c you get a^(b*c), you
    now have an equation with R all by itself on one side and other stuff
    on the other.
    4. write a program to implement the left side, given the weight, and
    out will pop the right side. The only problem is that you have to make
    sure you have consistent units. Briefly, to convert from one unit to
    another, e.g., pounds (mass) to kilograms, if you have a formula in
    terms of kg you may want to multiply by 1. But you write the 1 in a
    useful way:
    1 kg = 2.205 lb
    divide by the right hand side, you get
    1 kg/(2.205 lb) = 1
    You can multiply any formula by this 1 and not create an error. For
    example, suppose you know you weigh 220 lbs. You have
    MyWeight = 220.5 lb
    multiply by 1:
    MyWeight*1 = (220.5 lb)*(1 kg/2.205 lb) = 100 lb*kg/lb; cancel the lb
    and you get
    MyWeight = 100 kg.
    Easy, no? You just have to choose the right form of "1". For example,
    given MyWeight in lb, you would use 1 = (2.205 lb)/1 kg instead.
    Hope this helps. Good luck.
    P.S. Please sign your notes in the future. We don't like anonymous
    posts, much. Not your whole name and address, just a useful handle.
    Irl
    On Mar 24, 9:03 am, gotu...@aol.com wrote:
    > Let's say you have a ball (shpere) that weighs 10 pounds the
    > material is brass which have a density of .305 cubic feet. this is all
    > the information I have. How can I find the diameter of the ball. I
    > would like to program the formula on my hp50. thank in advance




  13. Re: need help finding a formula for my calc

    opticsmith wrote:
    [snip]
    > 1 kg = 2.205 lb
    > divide by the right hand side, you get
    > 1 kg/(2.205 lb) = 1
    > You can multiply any formula by this 1 and not create an error. For
    > example, suppose you know you weigh 220 lbs. You have
    > MyWeight = 220.5 lb
    > multiply by 1:
    > MyWeight*1 = (220.5 lb)*(1 kg/2.205 lb) = 100 lb*kg/lb; cancel the lb
    > and you get
    > MyWeight = 100 kg.
    > Easy, no? You just have to choose the right form of "1". For example,
    > given MyWeight in lb, you would use 1 = (2.205 lb)/1 kg instead.
    > Hope this helps. Good luck.
    > P.S. Please sign your notes in the future. We don't like anonymous
    > posts, much. Not your whole name and address, just a useful handle.
    > Irl
    > On Mar 24, 9:03 am, gotu...@aol.com wrote:
    >> Let's say you have a ball (shpere) that weighs 10 pounds the
    >> material is brass which have a density of .305 cubic feet. this is all
    >> the information I have. How can I find the diameter of the ball. I
    >> would like to program the formula on my hp50. thank in advance


    [Assuming that enough time has gone by now that any assignment is late,
    if indeed it is an assignment.]

    You don't need all the unit conversion stuff if you simply want answers
    in the same units as the original input values.

    So:

    1) From Google or a textbook, find that the formula for the volume of a
    sphere is
    v = 4/3*pi*r^3

    2) Enter this into the 50G as an algebraic expression:
    'v=4/3*pi*r^3'
    where pi is the symbol for Pi (left-shift space), and leave it on the stack.

    3) We also know that the density of the brass material of the sphere is
    1lb = 0.305 cubic feet

    4) So tell the calculator about this by entering the following equation
    and leaving it on the stack:
    'v/0.305=10'

    5) Now we've got two equations so we use the multiple equation solver.
    This expects to find the equations stored as a list in the special
    variable EQ. So first put them into a list by entering
    { }
    onto the stack. And then press + twice

    6) You should now have
    { 'V=4/3*pi*r^2' '.305*v=10' }
    on the stack. Store in EQ by executing the STEQ command.

    7) The multiple equation solver needs flag -117 (Soft MENU) set, so do
    that in the MODES FLAGS menu.

    8) Now press APPS, choose Equation Library and then press the MES menu
    key. This displays the Multiple Equation Solver menu.

    9) Press MINIT to initialise.

    10) Press MSOLV to start the equation solver.

    11) You should see R & V displayed black on white as the first two menu
    keys.

    12) Press left-shift R and you'll see the display flash up "Solving for
    V", then "Solving for R" and then you'll see:
    R:.853307602597

    This is the radius (in feet) of a brass sphere that weighs 10lbs.

    13) If you press right-shift V then you will see 3.05000000001 which is
    the volume (in cubic feet) of 10lbs of brass.

    HTH

    Of course this is all "magic" in that the calculator does everything for
    you. You might want to do the substitution for yourself on paper so that
    you can see what is happening.

    Regards,

    --
    Bruce Horrocks
    Surrey
    England
    (bruce at scorecrow dot com)

  14. Re: need help finding a formula for my calc

    What about temerature?? Is it cold?? How cold?? Is it cold enough to
    freeze the balls off of a steel monkey??

    Or could it be??


  15. Re: need help finding a formula for my calc

    Bruce Horrocks wrote:

    > 13) If you press right-shift V then you will see 3.05000000001 which is
    > the volume (in cubic feet) of 10lbs of brass.


    Which it isn't, of course, even with the supplied density value. My
    brain was addled at that point.

    Which means that R must be wrong as well. :-(

    Omigod the multiple equation solver is buggy - cue thread on rubbish
    calcs. ;-)


    --
    Bruce Horrocks
    Surrey
    England
    (bruce at scorecrow dot com)

  16. Re: need help finding a formula for my calc

    Spence wrote:
    > What about temerature?? Is it cold?? How cold?? Is it cold enough to
    > freeze the balls off of a steel monkey??
    >
    > Or could it be??
    >


    Actually, it's nicely warm outside at the moment. Will this make a
    difference?

    --
    Bruce Horrocks
    Surrey
    England
    (bruce at scorecrow dot com)

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