Axis Definition and 928 Threads

I have to draw cosine waves in relation to pattern formation for mathematical biology, for example, I have to plot things similar to these on the x-axis; cos( 2*pi*x / √5 ) from x= 0 to √5 cos( 3*pi*x / 2 √5 ) from x= 0 to 2√5 cos( 3*pi*x / 2 √(5/6) ) from x=0 to 2√5 And with the y-axis; cos(...

Homework Statement The curve x=y^(2) and the line x=4 is rotated about the x axis. Homework Equations pi* integral from a to b of Radius^(2) The Attempt at a Solution pi* integral from 0 to 4 of (square root of x)^(2) dx. My teacher has this answer as 8pi but I think that that...

Hello, I would like to know, how can I change units showed in axis. I would like to change those relative units (20000, 40000...) to μm. The conversional relation is 50 = 1μm, so instead 20000, 40000 i would like to have 400μm, 800μm. I enclose picture where it should be more clear what I am...

Homework Statement A circular loop in the XY plane of radius R and with current I moving in the counterclockwise direction. Compute B at (L,0,0) for L >> R0. Homework Equations Biot–Savart law dB= μ0I/4∏ *(dl X r)/r^2 The Attempt at a Solution I know that the B on the axis...

I recently read that the Earth's axial tilt fluctuates between 22 degrees and 24 degrees. Can someone explain what causes the tilt to change? If I assume the Earth is perfectly spherical, gravitational forces cannot change the tilt. So, is that the reason i.e. that the Earth is not perfectly...

I want to ask why a rod's rotational inertia with rotational axis at its end is not 1/2 mR2 but 1/3 mR2?

I was wondering if the angular momentum of anybody with constant \omega (angular velocity) about a point on the centre of the circular path and about any point on the axis of rotation is the same...

Homework Statement you have a +3C and a -1C charge on the x axis. the +3C charge is at the origin and the -1C is at x=1. At what point on the positive x-axis does E=0? Homework Equations E=kQ/r^2 The Attempt at a Solution So i have E=(-1k/r^2)+(3k/(1+r)^2) Setting E=0...

I was just wondering that when we have a molecule, and you introduce heat, the molecule starts to get translation, rotation and vibration energy. I'm considering just a molecule with two atoms and one axis which binds them together. Now the real question is that why is there only two axis in...

I've asked my self this question. How is it that when you spin a bicycle wheel in a vertical plane while holding the axil only on one side that the whole essembly doesn't comes tumbling down. OK, now I know how that is possible. What I'm wondering now is if you take that essembly and rotate it...

Homework Statement So here is the question: Matrix A corresponds to the linear transformation T obtained by first rotating a vector in R3 through angle ∏/3 about the z axis and then through angle ∏/4 about the x-axis. Find the parametric equation for the axis of rotation. Homework...

Hi, Concerning only the upper right quadrant of an ellipse... I know the distance from the center of the ellipse to the top of the ellipse, (semi-minor axis "b"), is 1000. I know the distance from the center of the ellipse to the side of the ellipse, (semi-major axis "a") is 1732. At the...

Hey guys, as the title says I can understand why the neutral axis does not pass through the centroid after reaching a point where the bending moment is max before the beam collapses. Say you have a straight structure supported by two double I-Beams and a weight in the middle. Why does the...

Hi I am studying Sports Science and researching the use of an accelerometer during specific wieght training type movements. I have a MEMS device (unfortunately I only have mininal details regarding it) which can measure upto 24G and 400Hz and comes with basic software that transfers the data...

The problem given is a perturbation on the two dimensional harmonic oscillator where the perturbation is simply: H'=-qfy. It seems that all of the elements of the matrix H' are zero and so constructing a diagonal matrix in the subspace is eluding me. Any ideas?

suppose I have two position functions in terms of time. One position function for the x component and the other for the y component. The y component is of constant acceleration. The x component is of constant velocity. How do I represent acceleration on a graph of this type? Here is an...

Homework Statement Which describes the electric field on the central axis through a ring of uniform positive charge? A. The field vectors point along the axis and toward the ring on both sides of the ring. B. The field vectors point along the axis and away from the ring on both sides of...

i.e. "A F = <0,0,10> is exerted at the point (1,1,1) what is the moment about the X axis?" i know the answer is <sqrt(3),sqrt(3),sqrt(3),> DOT (<1,1,1>x<0,0,10>) but the physical meaning of that escapes me. in what applications would an axis be more useful than a point? thanks!

Homework Statement Homework Equations given in question The Attempt at a Solution I already know the solution but I don't understand what it means the process is simply fixed(c,b,a) to euler(a,b,c) Rz(a)=Rz(a) Ry(b)=Rz(a)Ry(b)Rz'(a) Rz(c)=Rz(a)Ry(b)Rz(c)Ry'(b)Rz'(a) write it in fixed...

need help please in calculating semi major axis(SMA) of a binary star.. if for example the orbital distance of star A is 50AU and star B is 100 AU from the centre of mass what would the SMA be? is it as simple as the half way point ? ie 75AU? thanks in advance

HELP I don't understand at all Homework Statement Two positive point charges on the y-axis, each of which has a charge of 5.0 10-9 C, are located at y = +0.60 m and y = -0.60 m. Find the magnitude and direction of the resultant electric force acting on a charge of 7.6 10-9 C located at x =...

Hello, I'm having a problem finding the minor and major axsis lengths of an ellipse from three points, the ellipse's center, and two conjugate end point diameters. I have no problem solving the problem when the conjugate diameters align with the minor and major axsis, but when they don't the...

Is this question worded poorly or is it just me? Three charges are on the y-axis. Charges -q are at y = ±d and charge + 2q is at y = 0. (a) Determine the electric field E along the x-axis. (b) Verify that your answers to part a has the expected behavior as x becomes very small and very...

Could someone please clarify, i thought i understood but some reading has brought some confusion. As far as the gravitational value of free fall equations are concerned, is 9.8m/s or the 32ft/s (+,-) when the object is falling. The formula y=Vyo-1/2gt^2 chris

Homework Statement find the total area of the region between the curve and the x- axis Homework Equations 1) y=2-x, 0≤x≤3 2)y=3x^2-3,-2≤x≤2 3)y=x^3-3x^2+2x, 0≤x≤2 4)y= x^3-4x, -2≤x≤2 The Attempt at a Solution I've tried using my graphic calculator to see what the graphs looked...

Homework Statement DoCarmo Section 1.5 problem 1 part d. Show that the lines containing n(s) and passing through a(s) [a is the curve, and n(s) is the unit normal vector] meet the z axis under a constant angle of pi/2. Helix: a(s) = (a cos(s/c_, a sin(s/c), b*s/c), so I computed n(s) =...

Homework Statement Find the direction of vector R counterclockwise to the + x axis Homework Equations The Attempt at a Solution This kind of threw me off balance. I know to get the direction of the vector R for the problem is arctan (5.07/10.87) which gives me 25. However the...

I am not so sure how to explain this. But when looking at sqrt( 1 - v^2/c^2 ) for time dilation. It seems to follow that you may be able to think about it as 1 = v^2 + t^2 if look at v as fraction of c, and t as the amount a clock will be dilated. Then you could think about it in your frame...

1. This isn't homework, this is personal study, but i think it really fits the form of a "textbook style question". I need to find the volume of two intersecting circular cylinders of unequal radius and axis that don't intersect but are at right angles. 2. i have no relevant...

In an experiment to demonstarte relationship between current and p.d. in an electrilyte the book says to plot current on the Y axis. Why is this? V = IR R = V/I I always assumed when you plot graphs, the slope must equal the constant. Any input appreciated.

θHomework Statement Find the components N_{x} and N_{y} of vector N in the tilted cooridinate system. Homework Equations cosθ = adg/hyp and sinθ= opp/hyp The Attempt at a Solution The correct answer is supposed to be N_{x} = -Nsinθ and N_{y} = Ncosθ The error...

Hi guys I was trying not to post this as it is difficult to understand without the diagram, but I will try and give you a visual. Basically there are 2 pulleys attached together on the one pivot, the larger one is driven by a belt that is driven by a motor. The inner pulley is used to hoist the...

I'm just wondering about using a Mohr's Circle, do I need to use the same scale for the x and y axes, as surely otherwise my choice of scale greatly impacts the results. I am using one to get my principle second moment of areas, Ix and Iy, for an equal L section. Ix and Iy are where the...

Similar to my other thread https://www.physicsforums.com/showthread.php?t=557750 I think in this case I need to use triple integrals But what is the integrand and limits? Can someone please help me set it up? Here's all I know ∫∫∫dydx Please help I have my final next wednesday.

Homework Statement A biconvex symmetrical lens is cut in two halves and placed as shown in figure. if a point object is placed in the left how many images will be formed options - (a) Two images (b) Three images Homework Equations The Attempt at a Solution As I...

Two unequal masses m and 2m are attached to a thin bar of negligible mass that rotates about an axis perpendicular to the bar. When m is a distance 2d from the axis and 2m is a distance d from the axis, the moment of inertia of this combination is I. If the masses are now interchanged, the...

LEASE HELP! -Add an axis to current rectangle -Draw both piece of arm -rotate object first axis 20 degree --redraw. -then, rotate 2nd part about 2nd axis to -30degree my current code for rectangle is %RECTANGLE('Position', [x y w h]) w=4.5; %width h=.5; %height x=1.75;y=2.75...

This is about a little thing that I have a lot of trouble understanding, and which always bugs me when studying equilibrium. I've often tried to apply the concepts of torque in this context, but nothing ever seems to make sense. I consider a uniform rod which is initially at rest, and is not...

Look at picture for more details... Book says... " A body is free to rotate only about the z-axis. Within the body any particle of mass m can move only in a plane parallel to the xy plane." What would the xy plane look like? I am assuming by "xy plane" this does not mean x and y axis...

Homework Statement An homogeneous rod is fixed to an extremity and is rotating around a vertical axis, doing an angle of theta with the vertical. (in the scheme I made I wrote alpha but it's theta! (θ)) If the length of the rod is L, show that the angular velocity needed to make it turn...

Neutron stars are thought to be rotating in a way that their beems are seen as the pulses. The beems are not aligned with the axis of rotation. What is the current theory about the speed of the axis of rotation? Are they spinning and rotating on both axis?

In my textbook, it says that when a ball rolls down a surface, inclined or not, the point of contact can be thought of as the pivot or the axis of rotation, since at the point of contact, the ball's velocity is zero. Makes sense, but then the textbook becomes inconsistent in problems solving...

I have in my problem, a ball sitting on a cylindrical rod that pivots at the bottom, some guy in the explanation said parallel axis theorem and came up with moment of inertia of: I = (mL^2)/3 + [2Mr^2/5 + M(L+r)^2] where L is the length of the rod, m is the mass of the rod, M is the mass of the...

As a result of friction, the angular speed of a wheel changes with time according to dθ/dt = ω_o*e(-σt) where ω_o and σ are constants. The angular speed changes from 3.50 rad/s at t=0 to 2.00 rad/s at t=9.30s. (a) Use the information to determine σ and ω_o. Then determine (b) the...

Hello All, I'm currently in the process of designing a numerical model for a vertical axis wind turbine, more specifically, a straight blade giromill. I'm currently having trouble because depending on the variables I choose, I can produce more power than available from the wind. My...

I am writing a little code that should make an object revolve around a tilted axis. Here is what I have: -The center coordonates -A normal array (3 numbers between 0 and 1); -position of the object. Is there a way to do this? I think...

Hello, Does anyone know if this makes sense or is usable? I've only been able to describe it through a graph. Instead of the x-axis being numbers, being powers of x. Let me clarify - where normally would be x=0,1,2,3... would now be x^0, x^1, x^2, x^3 and the y-axis would be values of...

Let the elliptical orbit be bisected through the semi-minor axis... Ellipses are symetrical and both sides here are mirror images of each other, true? If so, then they share matching curvature at opposite ends of the semi-major axis (and opposite ends of the semi-minor axis, and reflections...

In rotational mechanics i am mostly confused with the axis of rotation. Let me give you some examples of question. about which axis. Is that instantaneous axis of rotation. OK this may seem to be solved here but what about this question. Now once again. which axis should i choose...

Hi all, I am having a little trouble with a MATLAB GUI that i am writing, with GUIDE. Its purpose is basically to display the bode diagram and step response of a transfer function, and allow the user to change controller parameters/time delays and such to see the affect. I won't post my code...