Optimization problem, minimal speed of point












-1












$begingroup$


What is the minimal speed of a point moving according to this law:$$S(t)=t^3+3t+1$$ $[m], t-[s]$

Will I get the answer by finding the global minimum of this function? Or is it about finding a point where function declines the most? I'm lost










share|cite|improve this question









$endgroup$












  • $begingroup$
    What does $S(t)$ represent here? Speed? Position?
    $endgroup$
    – pwerth
    Jan 9 at 18:37










  • $begingroup$
    Does $t$ stand for time?
    $endgroup$
    – pendermath
    Jan 9 at 18:37










  • $begingroup$
    Yes t stands for time in seconds
    $endgroup$
    – B. Czostek
    Jan 9 at 18:38










  • $begingroup$
    Does $S(t)$ represent position?
    $endgroup$
    – KM101
    Jan 9 at 18:46












  • $begingroup$
    Be careful: in general “speed” is not the same thing as “velocity,” although happily in this case the velocity is always positive.
    $endgroup$
    – amd
    Jan 9 at 20:26
















-1












$begingroup$


What is the minimal speed of a point moving according to this law:$$S(t)=t^3+3t+1$$ $[m], t-[s]$

Will I get the answer by finding the global minimum of this function? Or is it about finding a point where function declines the most? I'm lost










share|cite|improve this question









$endgroup$












  • $begingroup$
    What does $S(t)$ represent here? Speed? Position?
    $endgroup$
    – pwerth
    Jan 9 at 18:37










  • $begingroup$
    Does $t$ stand for time?
    $endgroup$
    – pendermath
    Jan 9 at 18:37










  • $begingroup$
    Yes t stands for time in seconds
    $endgroup$
    – B. Czostek
    Jan 9 at 18:38










  • $begingroup$
    Does $S(t)$ represent position?
    $endgroup$
    – KM101
    Jan 9 at 18:46












  • $begingroup$
    Be careful: in general “speed” is not the same thing as “velocity,” although happily in this case the velocity is always positive.
    $endgroup$
    – amd
    Jan 9 at 20:26














-1












-1








-1





$begingroup$


What is the minimal speed of a point moving according to this law:$$S(t)=t^3+3t+1$$ $[m], t-[s]$

Will I get the answer by finding the global minimum of this function? Or is it about finding a point where function declines the most? I'm lost










share|cite|improve this question









$endgroup$




What is the minimal speed of a point moving according to this law:$$S(t)=t^3+3t+1$$ $[m], t-[s]$

Will I get the answer by finding the global minimum of this function? Or is it about finding a point where function declines the most? I'm lost







optimization maxima-minima






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Jan 9 at 18:35









B. CzostekB. Czostek

556




556












  • $begingroup$
    What does $S(t)$ represent here? Speed? Position?
    $endgroup$
    – pwerth
    Jan 9 at 18:37










  • $begingroup$
    Does $t$ stand for time?
    $endgroup$
    – pendermath
    Jan 9 at 18:37










  • $begingroup$
    Yes t stands for time in seconds
    $endgroup$
    – B. Czostek
    Jan 9 at 18:38










  • $begingroup$
    Does $S(t)$ represent position?
    $endgroup$
    – KM101
    Jan 9 at 18:46












  • $begingroup$
    Be careful: in general “speed” is not the same thing as “velocity,” although happily in this case the velocity is always positive.
    $endgroup$
    – amd
    Jan 9 at 20:26


















  • $begingroup$
    What does $S(t)$ represent here? Speed? Position?
    $endgroup$
    – pwerth
    Jan 9 at 18:37










  • $begingroup$
    Does $t$ stand for time?
    $endgroup$
    – pendermath
    Jan 9 at 18:37










  • $begingroup$
    Yes t stands for time in seconds
    $endgroup$
    – B. Czostek
    Jan 9 at 18:38










  • $begingroup$
    Does $S(t)$ represent position?
    $endgroup$
    – KM101
    Jan 9 at 18:46












  • $begingroup$
    Be careful: in general “speed” is not the same thing as “velocity,” although happily in this case the velocity is always positive.
    $endgroup$
    – amd
    Jan 9 at 20:26
















$begingroup$
What does $S(t)$ represent here? Speed? Position?
$endgroup$
– pwerth
Jan 9 at 18:37




$begingroup$
What does $S(t)$ represent here? Speed? Position?
$endgroup$
– pwerth
Jan 9 at 18:37












$begingroup$
Does $t$ stand for time?
$endgroup$
– pendermath
Jan 9 at 18:37




$begingroup$
Does $t$ stand for time?
$endgroup$
– pendermath
Jan 9 at 18:37












$begingroup$
Yes t stands for time in seconds
$endgroup$
– B. Czostek
Jan 9 at 18:38




$begingroup$
Yes t stands for time in seconds
$endgroup$
– B. Czostek
Jan 9 at 18:38












$begingroup$
Does $S(t)$ represent position?
$endgroup$
– KM101
Jan 9 at 18:46






$begingroup$
Does $S(t)$ represent position?
$endgroup$
– KM101
Jan 9 at 18:46














$begingroup$
Be careful: in general “speed” is not the same thing as “velocity,” although happily in this case the velocity is always positive.
$endgroup$
– amd
Jan 9 at 20:26




$begingroup$
Be careful: in general “speed” is not the same thing as “velocity,” although happily in this case the velocity is always positive.
$endgroup$
– amd
Jan 9 at 20:26










1 Answer
1






active

oldest

votes


















0












$begingroup$

If this is the displacement of the particle, we have:
$$V(t)=S'(t)=3t^2+3$$
Which is minimal where $t=0$ giving a speed of 3.



If this is the speed of the particle, the speed is minimal at $t=0$ giving a speed of 1.






share|cite|improve this answer









$endgroup$













    Your Answer





    StackExchange.ifUsing("editor", function () {
    return StackExchange.using("mathjaxEditing", function () {
    StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
    StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
    });
    });
    }, "mathjax-editing");

    StackExchange.ready(function() {
    var channelOptions = {
    tags: "".split(" "),
    id: "69"
    };
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using("snippets", function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: true,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: 10,
    bindNavPrevention: true,
    postfix: "",
    imageUploader: {
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    },
    noCode: true, onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3067805%2foptimization-problem-minimal-speed-of-point%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    0












    $begingroup$

    If this is the displacement of the particle, we have:
    $$V(t)=S'(t)=3t^2+3$$
    Which is minimal where $t=0$ giving a speed of 3.



    If this is the speed of the particle, the speed is minimal at $t=0$ giving a speed of 1.






    share|cite|improve this answer









    $endgroup$


















      0












      $begingroup$

      If this is the displacement of the particle, we have:
      $$V(t)=S'(t)=3t^2+3$$
      Which is minimal where $t=0$ giving a speed of 3.



      If this is the speed of the particle, the speed is minimal at $t=0$ giving a speed of 1.






      share|cite|improve this answer









      $endgroup$
















        0












        0








        0





        $begingroup$

        If this is the displacement of the particle, we have:
        $$V(t)=S'(t)=3t^2+3$$
        Which is minimal where $t=0$ giving a speed of 3.



        If this is the speed of the particle, the speed is minimal at $t=0$ giving a speed of 1.






        share|cite|improve this answer









        $endgroup$



        If this is the displacement of the particle, we have:
        $$V(t)=S'(t)=3t^2+3$$
        Which is minimal where $t=0$ giving a speed of 3.



        If this is the speed of the particle, the speed is minimal at $t=0$ giving a speed of 1.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Jan 9 at 18:45









        Peter ForemanPeter Foreman

        2,5441214




        2,5441214






























            draft saved

            draft discarded




















































            Thanks for contributing an answer to Mathematics Stack Exchange!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            Use MathJax to format equations. MathJax reference.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3067805%2foptimization-problem-minimal-speed-of-point%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            Human spaceflight

            Can not write log (Is /dev/pts mounted?) - openpty in Ubuntu-on-Windows?

            張江高科駅