Recent content by MathsRetard09

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    Slope and Deflection of a Simply Supported Beam

    The title is fairly misleading but is within the subject. I have drawn up a beam of my own as part of my classwork because what bothers me is how you would find Young's Modulus [E] and the second moment of inertia [I] without being given them. Every question I have looked at has given me...
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    Guitar Pickups - Shapes of magnets used and their importance

    I'm not electrical minded but I am wondering why my guitar pickup like most have the these rod shaped magnets. Why are they that shape and why is it important? I would like to make my own pickup to understand better how it functions and to see if I can achieve the attempt in making one...
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    Show that the wheel has constant retardation using calculus

    Figured it out guys. I wasn't using the calculus Retardation is basically decceleration - therefore it's acceleration so the value would be negative. Sorry not pi, sigma - that's my mistake appolagees Basically Angular Acceleration (alpha) = d2sigma/dt^2 Which basically means that...
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    Show that the wheel has constant retardation using calculus

    Homework Statement I am required to use calculus to show that a flywheel has constant retardation Prior to this I have found the initial angular velocity which is 60rad/s and the angular velocity after 2s which is 58.667rad/s Homework Equations pi=60t-(t^2)/3 dpi/dt = 60 - 2t/3...
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    Percentage Saving in mass/(weight) of a hollow shaft - equation?

    Homework Statement I'm looking for an equation that i can use to work out the percentage saving in mass gained by using a hollow shaft rather than a solid shaft. The question is simply that. I've done research and found a dodgy equation that doesn't work for me, this is below, and I...
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    Change in Angular Momentum Calculation

    @EricAngle - appolagies haha. @series111 - I've actually figured it all out now. My method is wrong because above I do this: (w2-w1)^2 But the correct method is (w2^2-w1^2) Therefore: 1/2 I (w2^2-w1^2). But glad you replied. Cheers.
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    Engineering Science: Torsion (Hollow Shaft replaced by Solid Shaft)

    Again thankyou, I do appolagise i did read your advice previously about the units being spaced from the digits, i guess i was just rushing with my typing which is what i normally do. I did manage to use some common sense since my previous post and yesterday did find a method very similar to...
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    Engineering Science: Torsion (Hollow Shaft replaced by Solid Shaft)

    Okay I've got everything planned out, i know where I've gone wrong, and its at the the start, my d value was wrong which meant it affected everything else. All i finally ask for is help with transposing the following equation to make (d) the subject: J = pi(D^4 - d^4) / 32 // d is to be...
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    Change in Angular Momentum Calculation

    This is wrong, from the handout I have the Angular Momentum = Iw(omega) There is no division of 2. Wikipedia though helpful, isn't the best source of evidence to use because anyone can edit it. Where did you get 3.918 kgm^2/s from calculating this: 48.98 kg * ( 0.4 m / 2 )^2 / 2...
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    Engineering Science: Torsion (Hollow Shaft replaced by Solid Shaft)

    nvn: Thankyou for your reply. If my dH value is wrong then, as i was regreting, my previous calculations were wrong. Thanks for this, i'll re-do it all again and see what i get. P.S. just to clarify - do i have the correct method?
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    Engineering Science: Torsion (Hollow Shaft replaced by Solid Shaft)

    Homework Statement Question Assuming the torque and maximum shear stress values to be the same for both shafts, determine the size of a suitable soild shaft which could be used instead of the hollow shaft. Information/Data Known Firstly, a previous question - A ship's propellar...
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    Why is the Maximum Bending Stress in a Hogging Beam Compressive at the Bottom?

    Homework Statement Question: Sketch the cross section of the gantry girder and indicate on it the position of the maximum bending stress. State if this stress is tensile or compressive for this particular example, explain how you decided Homework Equations There aren't any required...
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    Simply Supported Beams - Stuck On A Question

    I have a sheet titled 'Tables of Properties' On it are Universal Beams, Structural Tees and Gantry Girders. Before this question i drew a simply supported beam with two UDL's, a SFD and a BMD, But that is irrelevant to this erm... My maximum bending moment was 120kNm however on my BMD...
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    Simply Supported Beams - Stuck On A Question

    Homework Statement This is the question i am asked: Determine a suitable size for the (gantry girder) beam selected from standard section tables. Prior to that is some information: The cross-section of the beam shows that of a Gantry Girder. The maximum bending stress in the girder...
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