Angles Definition and 892 Threads

So I'm trying to check the moment of inertia Ix for this weird I beam. The three steel plates' moments of inertia were easy enough to calculate. However, I would appreciate any help on how I should go about calculating the contribution of the four L6x6x1 angles to the total moment of inertia...

Hello, I have attached a diagram of QPSK modulation angles. I was wondering how would the red and yellow dots be interpreted. Those dots are not exactly on either of the 4 different phase angles. But I understand QPSK has a discrimination of 90 degrees so would the red equate to 45 degrees and...

Homework Statement α=30° β=45° m=10kg a=0 Tα=unknown Tβ=unknown THE ANSWERS SHOULD BE Ta=72N, Tβ=88N Homework Equations mg=10kg*9.8m/s2=98N ∑Fx=ma(x)=0 ∑Fy=ma(y)=0 A Free Body Diagram would show three forces: 98N facing downwards, Ta facing 30° up and to the left, and Tb...

I am trying to figure out what size eaves we need for our house extension. I've tried a few calculations and now I'm posting here in the hope that a logical thinker will be able to tell me what I'm doing wrong. We live in Adelaide, Australia, and we want to put in glass double-doors on a...

Homework Statement Here is the problem: A variable capacitor has seven armatures in the shape of half-circles with a radius of 2 cm. The armatures have a distance of 1 mm separating them. Find the capacity when the angle θ is: (a) 0 degrees; (b) 45 degrees; (c) 135 degrees. Homework...

Homework Statement Two vectors A and B have precisely equal magnitudes. In order for the magnitude of A+B to be 120 times larger than the magnitude of A-B , what must be the angle between them? Homework Equations None (i think) The Attempt at a Solution A+B=120(A-B)...

Homework Statement A spider is resting after starting to spin its web. The gravitational force on the spider is 0.165 N on the junction of three strands of silk. The junction is supported by different tension forces in the two strands above it so that the resultant force on the junction...

Hi can anyone help me out with finding the interior angles of a pentagon on a sphere. I know two of the interior angles already and I know all the angles that correspond with the arc lengths of the sides of the pentagon. How do I find the other three interior angles? Thanks

Cyclopropane is a cycloalkane with three carbon atoms. Each carbon is bonded to two hydrogens as well as the other two carbons, forming a triangular bond between the three carbons. Each carbon has a tetrahedral molecular geometry since it has sp3 hybrization. However, I am rather confused...

Homework Statement A meter stick is at rest in the laboratory frame. It lies in the x-y plane, making an angle of 30° with the x-axis. What angle does this meter stick make with the x'-axis of a reference frame moving at V=0.8c in the x-direction. Laboratory frame is the rest frame...

Homework Statement We have ##4x+x+y=280^0##(degrees), find ##x##, ##y## and ##4x##. Homework Equations ##4x+x+y=280^0## The Attempt at a Solution ##4x+x+y=280^0## ##5x+y = 280^0## ##5x=280^0-y## ##x=\frac{280^0-y}{5}## ##x=56^0-y## ---------------------...

Ok I am a little stuck and really need some help as I am pretty new with physics...im not sure if this question is really simple or if i need a little algebra to help find the answer. Q : 10 units, 30 degrees counterclockwise from the positive side of the x-axis :25 units, 45...

Homework Statement This is the problem: ##a+b=##900 (degrees) ##a=\frac{b}{14}## Find a and b. Homework Equations ##a+b=##900 (degrees) ##a=\frac{b}{14}## The Attempt at a Solution ##a+b=##900 ##(\frac{b}{14})+b=##900 ##\frac{b + 14b}{14} (14 and 14 get simplified)=## 900...

Hi, (attachment with visuals is included) I have a 3-D vector dataset that is measured in a reference frame (measurement reference frame) that is oriented relative to a horizontal coordinate system. In this dataset I have x-y- and z-component data for the vectors relative to a coordinate...

I have two angles: θ: and θ_{1}: θ_{1} = θ How do I differentiate the two angles? I want to say "leftward facing" and "rightward facing", but I'm not sure how to "mathematically." Note that I must talk about the angle that's between 0-90 degrees. Thanks, Ben

Homework Statement Let U = e^{iG_{3}\alpha}e^{iG_{2}\beta}e^{iG_{3}\gamma} where ( \alpha, \beta, \gamma ) are the Eulerian angles. In order that U represent a rotation ( \alpha, \beta, \gamma ) , what are the commutation rules satisfied by the G_{k} ?? Relate G to the angular...

Homework Statement Find all the unit vectors X element of R^3 that make an angle of pi/4 radians with vector Y = (1,0,1) and an angle of pi/3 radians with vector Z = (0,1,0) Homework Equations For any two vectors X and Y element of R^n, the dot-prodict of X and Y is equals to the...

SinX is defined for any angles [0,∞) ? Homework Statement SinX is defined for any angles [0,∞) Homework Equations Ok, the domain of sinX is -∞< x < ∞ The Attempt at a Solution Someone said "You are confused due to fact that Sin(-x)= - sin(x)." Does it mean that just because sinX...

I'm not looking for someone to work this one out for me, and I know I have done this type of problem in entry level physics, but it's popped up again in dynamics, and physics is mostly a blur these days. Given the muzzle velocity and impact coordinates of a rifle, find the angles of elevation...

I have learned a lot of formulas for converting trigonometric values, but when I looked up sin(pi/10) I got the exact answer (1/4)(√5 +1). I tried to arive at this using formulas, but I couldn't. How is this found? What other angles can be found exactly. Ps. I already know about how taylor...

Can you draw a force diagram to explain how a positive caster angle makes wheels return to a straight line in a shopping kart (as an example), while a negative caster angle would have the opposite effect. Thx

I have been reading about the normal vector to a point on a surface. http://mathworld.wolfram.com/NormalVector.html Can anyone explain if I have normals to 2 points on a surface and I want to compute the inclinations between them, how would one proceed?

See attachement for required information. Please and thank you!

What are the advantages to using one system to measure an angle over another. For example why do we measure angular velocity in radians instead of degrees? Are there any intrinsic advantages to one unit over another? Thanks AL

Hi all. I am trying to learn more on physics, and am at the subject on calculating work done. The formula to calculate work done is Work done = Force * Dislacement * consine(theta). I am on a question which explains: a 100N force is applied at an angle of 30 degrees to the horizontal to...

1. Homework Statement I'm choosing an angle for a diffraction grating such that a laser of particular wavelength λ is retroreflected (reflected back along incident path). 2. Homework Equations If you have a better way than using the equation below, feel free to explain. The book that I'm...

I'm choosing an angle for a diffraction grating such that a particular wavelength λ is retroreflected (reflected back along incident path). The book that I'm looking through treats the blazed diffraction grating as a set of N slits. This results in the equation...

Pretty simple question. When we draw triangles or other pictures with angles, when do we mark the angles as alpha and when do we mark them as theta? Is there some kind of convention or is it just whatever is free in the equation? It makes sense to me to use alpha for the first angle then...

Homework Statement This is not a homework question, I was just curious. I'm trying to find the angle θ that an unbalanced arm produces in the following case: Homework Equations τ=rF The Attempt at a Solution τ1=τ2 rF=rF r(98 N)(cos θ)=r(49 N)(cos θ) However, the cos θ...

I have three non-parallel vectors (whose components are known), v0, v1, v2 and I'd like to find a fourth unit vector, v3, given only the angles between: psi, angle between v0 and v3 theta, angle between v1 and v3 phi, angle between v2 and v3 I know that they are related by the dot product: v0...

Homework Statement Two forces act on a 4.00 kg mass which is sitting at rest on a horizontal frictionless surface. One force is 6.50 N directed 55° West of South, the other is 7.00 N directed 25° North of West. What acceleration does the mass receive? Homework Equations sin = o/h...

I am stuck on the job; I need to find the angles. It’s not an angle or side based triangle, just a right triangle. The lengths are known, A-B-C. What I need to know is the angles, a-b-c. So, a=90*, what formula could I use to find b, and c? Sorry, please make it easy enough for me to work it...

Homework Statement A kayaker needs to paddle north across a 100-m-wide harbor. The tide is going out, creating a tidal current that flows to the east at 2.0 m/s. The kayaker can paddle with a speed of 3.0 m/s. Homework Equations v= v + V Let the Earth frame be S and a frame attached...

The idea of a circle divided into 360 degrees that goes clockwise has been around for thousands of years (see orienteering compasses). So, why do radians and angles in trigonometry go counter-clockwise and start off pointing to the right? Was that on purpose?

Homework Statement A ball of weight 5 Newtons is suspended by two strings as shown above. Determine the magnitude of each of the forces, T1 and T2. (Note: sin 37° = 0.6; cos37° = 0.8) Homework Equations T = mg The Attempt at a Solution I couldn't go anywhere because I need a...

Say I have an odd shaped rigid body in pure rotation. I fix an orthogonal x-y-z coordinate system to the body, and coincide the origin of this coordinate system to the origin of my global coordinate system X-Y-Z. I have 3 Eulerian angles (as functions of time) which I can use to describe the...

I'm researching an abstract geometric property and I've discovered the problem depends on showing these two angles are equal for strictly positive x: arctan(x) - arctan(x^3 +2x -((x^2 + 1)^(3/2))) and -arctan(x) + arctan(x^3 +2x + ((x^2 + 1)^(3/2))) Any help would be greatly...

The manual lathe I work on has a degree scale for the arm. I have the radiuses in mm and the diameters in mm of two zones I have to cut. What formula can I use to determine the angle which delimits the two zones? For example: Say I have an item 15mm in diameter. Inner zone A is to have a...

Homework Statement Can you have a negative angle, or do you just assume absolute numbers? Your coach tells you to turn south for 10.0m and then turn and run east 15.0m. How far must the ball be thrown from where you started to where you ended? Homework Equations a^2 + b^2 = c^2...

Homework Statement I am having a nightmare doing homework for my physics test. I have figured out part of the answer but can not figure out what the angle of the displacement is and its driving me crazy... The teacher showed us two methods of how to find the answers, but ended up making...

Hi guys, I had been wondering for a while why it is that we use the radian as the unit of angular measurement in higher sciences and mathematics (calculus, physics, engineering) as opposed to the degree. In reviewing the relationship between the degree and radian, I believe that I have...

First, I struggled with whether to put this in advanced or intro physics. I read the sticky, and since this is a 300 level class that is taken at the junior level in the physics BS program at my school, I put it here. If it's considered too simplistic for advanced physics, I apologize. I've...

Homework Statement Suppose a mountain is described by the function z = 10x^2 * y − 5x^2 − 4y^2 − x^4 − 2y^4 and that you are standing at the point (1,1,−2). The positive x-axis points east and the positive y- axis points north. If you walk in the northeast direction what angle above the...

Homework Statement Previous part of the question I have solved: Express cos(2x) in terms of sin(x): I got this answer: cos(2x)=1-2sin2(x) Hence or otherwise solve the equation cos(x) + 3sin(x/2) = 2 Homework Equations Double angle formulae: cos(2x)=cos(2x) - sin(2x)...

Car Truck Collisins w/ ANGLES! Homework Statement A blue car with mass mc = 431 kg is moving east with a speed of vc = 19 m/s and collides with a purple truck with mass mt = 1298 kg that is moving south with a speed of vt = 12 m/s . The two collide and lock together after the collision...

Homework Statement A weight of 5000 N is suspended by two cables. The object is at rest. The first cable is horizontal and the second makes an angle of 143 ° with the first cable. Find the tension of the first cable. Homework Equations Erm...I know it's something with sin or cosin...

I have 3 forces, I assume that the resultant is equilibrium, that is just a guess. a - 12N b - 5N c - 13N how do i calculate the angles between the forces. I think I have to use the cosine rule but am not really sure. I have a book Physics made Simple but it doesn't really help Alan

Using Mathematica, I need to define a discrete probability distribution of N equally spaced angles on the interval [0, 2Pi], which isn't exactly uniform. More precisely, I need the distribution to feature a "Poisson-like" behavior : the angles should be randomly selected by random "packs"...

We usually describe angles in two dimensions (x and y plane). What is the mathematics behind three dimensions?

I'm trying to figure out what formula to get started in this question: A 7kg bowling ball moving with a velocity of 8 m/s strikes a single pin of mass 1.36kg. The impact deflects the bowling ball 10 degrees from it's original path. The pin moves along a path 45 degrees from the original path...