IGCSE Physics: Principle of moments and weights on bridges

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  • Опубликовано: 25 дек 2024

Комментарии • 74

  • @AbdulRahman-pr4vo
    @AbdulRahman-pr4vo 4 года назад +6

    Im here after 8 years it was posted

  • @thwin7953
    @thwin7953 6 лет назад

    Our school teaches O level physics and chem to freshmen and THIS VIDEO HELPED ME A LOT. I swear I don't even feel like crying or burning my textbook anymore. TYSM!

  • @walnut9921
    @walnut9921 6 лет назад +2

    Thank you so much for this! Great help before the exam!!

  • @NadaJBfan
    @NadaJBfan 10 лет назад +11

    So glad you remind us of the PoM during the video.

  • @m33sh50
    @m33sh50 2 года назад +1

    hi i was just wondering for the last question if you were not given force a or b and only force w with the length of w to a and b. how would you then work out force a/b????

  • @kanokochan8671
    @kanokochan8671 4 года назад +19

    I have a question that even i dont understand

  • @9501599
    @9501599 5 лет назад +1

    Hi there I am building a model of a railway bascule bridge and I was wondering because the bridge has a length forward of the pivot point and a weight at the rear to counter the forward length, how does the principal of equalibrium work as the bridge rises and lowers. The counter weight has to be calculated based on the PoM as you demonstrated but how is the weight of the counterweight calculated? I sorry if this question is somewhat inane but I am not very good with math and I over think these sort of things but I thought I would ask. Cheers

  • @stephendube5519
    @stephendube5519 8 лет назад +5

    very useful indeed.

  • @diptihehehe2768
    @diptihehehe2768 7 лет назад +1

    A uniform metre rule pivoted at 30cm is in equilibrium.
    A mass if 40kgf is suspended at 25cm from the fulcurm.
    Find the mass of the metre rule.

  • @DannyVampire14
    @DannyVampire14 8 лет назад +1

    So, how do you do it if they gave you one force (lets say 500) on a beam and two distances (i.e 2m and 3m) how do you find the clockwise and anticlockwise moments about a and b. I know that the answers are two numbers that add up to 500 because PoM applies but I dont know how to find them out, there's some big equation in the middle. Could u help me?

    • @RGSPhysicsDepartment
      @RGSPhysicsDepartment  8 лет назад +1

      +Danny Jones @IGCSE they don't tend to ask this sort of question as a calculation. It's generally a wordy question. However, if you did want to solve it....
      1) You're right that the total upward force would be 500N (as there is no net force)
      2) you would take moments about one of the supports and go from there (this is a lot easier with a diagram!)
      lets say the weight is 2m from the left edge and we'll call the left edge A and the right edge B.
      The moment for the 500N weight = 500N x 2m = 1000Nm
      The moment for the support at B = 1000Nm too (PoM) = F x 5m
      Rearranging gives F = 1000Nm / 5m = 200N
      This means the force at A = 300N (500N - 200N) and this makes sense as the weight is closer to A so A has to contribute more force in order to attain the same moment as B.
      Any help?

    • @RGSPhysicsDepartment
      @RGSPhysicsDepartment  8 лет назад

      +RGS Physics there is an image at this point of the video which should help you visualise it 8:17

    • @DannyVampire14
      @DannyVampire14 8 лет назад

      +RGS Physics thank you so much... You do not know how much I appreciate it, there was this big blank space in the middle of this calculation that I couldn't solve, and you solved for me, thank you so much for your time, you are amazing, and you were great help....Really appreciate it

    • @RGSPhysicsDepartment
      @RGSPhysicsDepartment  8 лет назад +1

      No worries

  • @amina5684
    @amina5684 3 года назад +1

    so the weight of the bar will be 400N?

  • @mohfa1806
    @mohfa1806 3 года назад

    Thank you for your beautiful videos...i have question please : in the bridge example , where is the axis of rotation ? , why you consider the location of the box as the axis of rotation being over a straight beam?..thank you

    • @yasmeenshaikh7788
      @yasmeenshaikh7788 3 года назад

      Hey there bud. Principle of moments can also be applied in questions like the bridge one. If you see a similar question like the bridge, if the object appears to be balanced or it is mentioned to be balanced then apply the principle of moments.

  • @SanjayKumar-mu9qo
    @SanjayKumar-mu9qo 7 лет назад

    thank u very much.. I had no physics tutor and I had this doubt.. thank u

  • @natsu3948
    @natsu3948 9 лет назад +11

    soooo verrryyy helpful

  • @x.x206
    @x.x206 4 года назад +4

    When moments are in equilibrium why cant we use cross multiplication. As in the second example : 20N -> 0.5 and x=40N and then we cross multiply but we dont get 0.25 which is my question? Please anyone answer :)

    • @josephchay3491
      @josephchay3491 4 года назад +1

      Here’s my understanding :
      It can’t be cross-multiplied because it’s not 0.5/20=x/40 or 20/0.5=40/x which will get you x=1
      But it’s 0.5*20=x*40 or vice verse which will give you x=0.25
      I hope this helps :)

    • @garycamilo7657
      @garycamilo7657 3 года назад

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      I somehow forgot the login password. I would love any tips you can offer me!

    • @maddenkarter3534
      @maddenkarter3534 3 года назад

      @Gary Camilo instablaster ;)

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    • @garycamilo7657
      @garycamilo7657 3 года назад +1

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      Thanks so much, you saved my account !

  • @kaylinbphillips
    @kaylinbphillips 4 года назад +2

    Thank you

  • @zuhrajb381
    @zuhrajb381 3 года назад

    Thank you very much , was very helpful .

  • @hassambukhory3008
    @hassambukhory3008 7 лет назад +3

    Great job !! Thank you so much ... it really helps ! ☺☺

  • @pakkuadnan
    @pakkuadnan 7 лет назад

    thanks. very easy to understand. really appreciate it

  • @juslina_sathguru
    @juslina_sathguru 8 лет назад +1

    Why do you not use the weight ?

  • @techiehelper1114
    @techiehelper1114 2 года назад

    Yesssss Mr Saunders

  • @Hazeem
    @Hazeem 8 лет назад

    Thanks so much, helped me for an upcoming test tomorrow with someone who strangely sounds exactly like you...

  • @michkailrichards8200
    @michkailrichards8200 9 лет назад

    Well done.... Thank you
    Good job 👏

  • @AshLey-uf6sy
    @AshLey-uf6sy 8 лет назад +1

    thank you
    major help

  • @fireflyschapstick
    @fireflyschapstick 5 лет назад

    Thankyou so much this really helped

  • @Fasken2
    @Fasken2 9 лет назад +2

    Interesting

  • @sohailjaswar6442
    @sohailjaswar6442 3 года назад

    so helpful

  • @ultra_gaming411
    @ultra_gaming411 6 лет назад +2

    Awesome one.... i liked it +1 sub you rock baby... thankyou

  • @geo5440
    @geo5440 4 года назад

    thanks bro, saved my ass from test tmr

  • @surd5876
    @surd5876 3 года назад +1

    2:11

  • @iAmori3
    @iAmori3 3 года назад

    you spelt equilibrium wrong but very very useful

  • @punoflife3397
    @punoflife3397 7 лет назад

    Thanks

  • @joeljose78
    @joeljose78 4 года назад

    nice light sabre 6:10

  • @abdullahsheikh715
    @abdullahsheikh715 7 лет назад +1

    tnx

  • @sultanhijazi9089
    @sultanhijazi9089 10 лет назад +1

    thanks man!

  • @cheriekeawelsh5794
    @cheriekeawelsh5794 5 лет назад +2

    Sigh thank you

  • @FineTimes01
    @FineTimes01 4 года назад +3

    0:0

  • @mango8793
    @mango8793 5 лет назад

    What grade is this video for?

  • @saadfarooq917
    @saadfarooq917 8 лет назад

    Thanks a lot :)

  • @johnwickspencil437
    @johnwickspencil437 5 лет назад +2

    Next year appearing for the cie exams

  • @thefantasytheater2607
    @thefantasytheater2607 5 лет назад +5

    Today is my paper ... Pray for me 🙏

  • @jakepaterson687
    @jakepaterson687 4 года назад

    ok

  • @upamajety5143
    @upamajety5143 7 лет назад +1

    Newton mteres!!!!

  • @ItsAlekhya_
    @ItsAlekhya_ 4 года назад +1

    Please be clear u were not audible sometimes in the video👎👎👎👎👎👎👎

  • @Aisha-gd6dq
    @Aisha-gd6dq 2 года назад

    Thank you