Recent content by KV-1

Problem: I do not know how to approach this problem. For a beam which has two reactions, the shear stress is equivalent to the reaction. I suppose that the stress is calculated using moment some how. But how? For seeing if the beam is allowable stress design compliant, you can use the...

I found out this is commonly done using several rules of thumb, feel free to ask about them in this thread

I need help calculating the size of the wood members I need in my truss. I understand the basics; I first need to calculate the load, then the stress on each member, then pick a wooden member which has that stress with a safety factor of let's say 2.0. The reason why I want to perform the...

What is the difference between the unit dead load and the unit weight of a material? For example, the unit weight for structural concrete is 145lb/ft^3. What would the unit dead load be? 145lb?

A roof purlin, supported by a roof rafter must support a 300 lb vertical snow load. Determine the component of of the snow load as a concentrated load “P” both perpendicular and parallel to the axis of the rafter. I read that the perpendicular component of the 300lb force can be figured out by...

Oh thanks! Not sure though, I think I found some equations that give me the desired points without having to interpolate though... It helps to know how this can be done though!

Hello! I am wondering if it is possible to establish a relationship between three sets of points (x,y,z) by interpolating. Basically i need a function that takes x and y and gives me a z that matches the following points: 130 472 5 130...

Hello, I have the following points that need to be fitted with a curve: (1,20);(2,4);(5,3) I'm wondering how to use the http://en.wikipedia.org/wiki/Lagrange_polynomial to do this. If possible, can these points be fitted with a cubic function? I tried to fit a cubic to this, but...

Nope, no separate derivatives needed. I don't remember the proof, but if its a natural log involving an absolute value, the derivative would be the same for f(x) if abs() wasn't there. Do you want me to find it? Also.. why are you factoring things? Just use the chain rule. d/dx (ln|w|) =...

Jalo , use google! https://www.physicsforums.com/showthread.php?t=153587 =P same problem as you

A little late, But this might help those struggling with the same problem. Use a dymaxion map--simplify a sphere into a polyhedron: http://en.wikipedia.org/wiki/Dymaxion_map http://upload.wikimedia.org/wikipedia/commons/b/bb/Dymaxion_2003_animation_small1.gif and then transfer...

((-0.76)(log(e)))/((-0.76x+305)(log(1.5)) thats the answer i think... in case anyone is curious

yes, but there seems to be truly no need for the chain rule, as log(1.5) is a number, equal to 0.176091 so it seems i just multiply the derivative of [log base 10 (-0.76x+305)] by that number!

1. my function is: f(x)=log 1.5 (-.76x+305). f(x)= log base 1.5 of -.76x+305 3. How do i differentiate it? here is what i have so far: (1/((-.76x+305)ln1.5))*(-.76/dx)

Hah, It's actually (b^2-a^2)/b for the answer... don't know why, but the y-mx+b yielded the correct answer... less room for mistakes there! thanks a lot though Mark44