Recent content by Emzielou83

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    Velocity feedback damping in aircraft

    Describe velocity feedback damping in relation to aircraft systems? my attempt at an answer: I know what damping is, and i know what velocity feedback is, I just can see how they fit together. I think it's something along the lines of; an auxilery power unit has a speed sensor...
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    Calculating Thrust in Propeller Engines: Can Anyone Help?

    Thanks very much. It seems so simple now, just couldn't see it. Thanks again
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    Calculating Thrust in Propeller Engines: Can Anyone Help?

    Can anyone help me? I'm doing a question on aircraft propulsion technology and I'm stuck. The question is: 'If the mass of air through a propeller is 1000 Kg/s, the aircraft's velocity is 100 m/s and the slipstream velocity is 120 m/s, calculate the thrust? Attempt at answer...
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    How Do You Calculate Thrust in Aircraft Propulsion Technology?

    Can anyone help me? I'm doing a question on aircraft propulsion technology and I'm stuck. The question is: 'If the mass of air through a propeller is 1000 Kg/s, the aircraft's velocity is 100 m/s and the slipstream velocity is 120 m/s, calculate the thrust? Attempt at answer...
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    How to Calculate Currents in an A.C Network?

    Hi, This is a coursework question from my Eng science. An A.C network consists of a coil of inductance 10mH and series resistance of 25 ohms in parallel with a 50*10-6F capacitor. The A.C supply voltage is 120/0 degrees V at 400Hz. Draw a well labelled diagram a) Calculate the current...
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    Axial loads and columns selection

    nvn: I have done the FS*P calculation and it works out as 1350kN, (3*450kN). So in MPa would be 1350/7^2 = 27.55 kPa, (kN/m^2). Is this correct? I'm still confused over the rest of it though, mainly because I keep coming out with the wrong answer. Using the formula: P = pi^2EI/L^2...
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    Axial loads and columns selection

    Thanks both for your help. I have found the eulers formula: P = pi^EI/ L^2 After transposing the formula to find I : putting in my numbers of: P= 450 kN E = 200 GPa L = 7 m I am not sure what these units are (m2/cm2 etc) because E is in GPa and I don't know if I was supposed...
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    Axial loads and columns selection

    Hi, Thank you for your reply. I don't really know what an axial load is! I can't find it in my textbook. Is it known as something else? Am I right in thinking the symbol for an axial load is P? I have looked on the internet but can't seem to find any formulas to work this out...
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    Axial loads and columns selection

    Hi, I have a question from an engineering science assignment that I'm stuck on. 1. Select the lightest wide flange section that can be used as a steel column 7 m long tosupport an axial load of 450 kN with a factor of safety of 3. Use 200 MPa as the limit of elasticity, 200 GPa as the...
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    Calculating Reaction Forces and Maximum Bending Stress in Simply Supported Beams

    nvm: my bending moment diagram goes up to maximum point at 5 m. I know it should start decreasing at 4 m, because max moment occurs at the 4 m point where the 45kN is acting upon the beam. Whatever way, (from right end or left end), I work out the moments at the 5 m point it works out to be...
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    Calculating Reaction Forces and Maximum Bending Stress in Simply Supported Beams

    Jay, I have drawn a bending moment diagram and a free body diagram (how correct they are I have no idea!). I have my max bending moment happening 1m from one end being 75.96. Th emax bending moment 2m from the one end where the 45kN is works out to be 61.53kNm. I have worked this from both...
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    Selecting Lightest Wide Flange Steel Column for 450kN Load

    Hi all, I need some help. Select the lightest wide flange section that can be used as a steel column 7m long tosupport an axial load of 450kN with a factor of safety of 3. Use 200MPa as the limitof elasticity, 200GPa as the modulus of elasticity and assume that the column issimply...
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    Calculating Reaction Forces and Maximum Bending Stress in Simply Supported Beams

    nvm: Also the correct answer should be Elastic modulus Z=512.8 cm^3 I don't really understand what i am supposed to be working out...Elastic modulus (which I am given!) or bending stress. Thanks Emma
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    Calculating Reaction Forces and Maximum Bending Stress in Simply Supported Beams

    nvn: Thank you for your reply. Sorry that I did not put the units in...this was just me being sloppy! Radius of gyratio = 14.29 cm Second moment of area = 10 087 cm^4 Elastic modulus = 571.8 cm^3 Plastic modulus = 653.6 cm^3 I also have the depth of the beam = 352.8 mm and the...
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    Calculating Reaction Forces and Maximum Bending Stress in Simply Supported Beams

    Jay, sorry to bother you again but I am stuck...again! The next part of the question asks me to ... 'Determine the actual maximum bending stress of the selected beam, taking into account the actual weight of the beam as a udl and check whether your selection is still appropriate by...
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