Recent content by Bohr1227

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    Momentum Equation for compressible 1D flow

    Homework Statement Derive the differential momentum equation: dp=-\rho udu. Homework Equations \oint_{ CS}^{ } \rho \vec{U}(\vec{U}\cdot \vec{n})dA=-\oint_{ CS}^{ } p\vec{n}dA for steady state flow... The Attempt at a Solution I tried to solve it like in the attached picture, but can someone...
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    Pressure gradient along a streamline using CV analysis

    You are right, I did not review it. I'm sorry, but it is fixed now. Thank you!
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    Pressure gradient along a streamline using CV analysis

    Sorry about the first post, I didn't review the latex, and apparently it is not possible to edit it...so here is the edited version: 1. Homework Statement Use a CV analysis to show that an element of fluid along a streamline gives \frac{\partial p}{\partial x}=-\rho u\frac{\partial...
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    Pressure gradient along a streamline using CV analysis

    Homework Statement Use a CV analysis to show that an element of fluid along a streamline gives \[\partial p/\partial x=-\rho u\partial u/\partial x\] Homework Equations \[\sum F=\oint_{CS}^{ } \rho \overrightarrow{V}(\overrightarrow{V_{rel}}\cdot \overrightarrow{n})\] The Attempt at a...
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    Damping ability in rubber wheels

    Homework Statement I don't have a specific question, but I try to calculate very easy on a simple Gokart in a project. I try to figure out if there is a way to approximately determine what the damping ability of rubber wheels is because I don't have any suspension on it. Homework Equations I...
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    Calculate forces on a double scissor jack

    I'm sorry, I have a motor that holds the bar between the jacks together, so it is a force F holding the lower right leg in place. I'm most interested in finding where and how big the maximum stress is, so I can choose the right cross section for it.
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    Calculate forces on a double scissor jack

    Homework Statement Find maximum forces in one given jack assembly. If I don't make it any easier, I will have 15 unknown forces, so I tried to just take the weight forces at the top...is it an okay assumption? If not, what should I do? My attempt on a solution is underneath. Thanks for tips and...
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    Find beam stress in a beam with varying cross section

    Something like this. The forces come from the wheel because they are supporting a weight.
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    Find beam stress in a beam with varying cross section

    Hi, the problem is to design a beam by myself. I don't have any spesific dimensions. The problem is that I don't know how to deal with it when it goes from one cross section to another. I have tried to look it up on online, but didn't find anything. I just know that it should look something like...
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    Find beam stress in a beam with varying cross section

    Homework Statement Hi, I'm trying to figure out how to calculate the stresses in my beam. The cross section varies (shown in the picture), and I don't know how I'm supposed to think to find the maximum stress. I appreciate tips or links to learn how to do it. Thanks. Sorry if the picture is...
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    Lift a hemispherical dome filled with water by rotating it

    I'm sorry, I have tried to make the problem clearer now :)
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    Lift a hemispherical dome filled with water by rotating it

    Homework Statement A hemispherical dome filled with water, radius 2 m and weight 30 tons, can be lifted by giving it a constant angular velocity around its vertical line of symmetry. The dome has a hole on the top. Decide the minimum angular velocity. My answer is 2.91 rad/s . The correct...
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    Which metals undergo differential aeration corrosion?

    Hi, I am trying to learn about different types of corrosion. I have read that iron can undergo differential aeration corrosion, but not zinc and aluminium. I do not see why...both can be reduced by oxygen and both have a passive film. Can somebody explain why? Thanks
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    Battery and torque in a hand drill

    Hey, I have a project where my group needs to design a drill. I am wondering if anyone here knows how to calculate the torque we get from 3 AA-batteries on 3.6 V (10.6 V together). How does it work? It just needs to assemble furniture, so we don't need very much force on it. Do you know what...
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    Equivalence principle - light beam through a rocket

    An observer outside the rocket sees a light beam through a rocket that's accelerating. How will an observer inside the rocket see the light beam? (The problem is showed in the picture below) My friends and I had this problem at school today, and we couldn't decide which is right. Here are our...
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