Angles Definition and 911 Threads

  1. B92X

    List of drag coefficient for basic shapes has no angles

    When I type "drag coefficient" in Google, and view some of the images, the standard list of geometrical shapes come into view, such as this one: https://upload.wikimedia.org/wikipedia/commons/thumb/3/37/14ilf1l.svg/220px-14ilf1l.svg.png If we take the cone for example, there is a drag...
  2. G

    Angles inscribed in circles part 1

    Homework Statement OK, I am new to these kinds of problems and I am trying to learn the appropriate properties but they are proving somewhat difficult for me... I hope I am going in the right direction. Homework Equations [/B] The first problem corresponds to the figure with 'Rep' in the...
  3. J

    MHB Find Rhombus Angles: 360º & 22º30

    The angle between the diagonal and the side of the rhombus is 22º30’. Find rhombus angles. Rhombus interior angles are 360º that much I know, but how do I find out the other angles?
  4. Cocoleia

    Particle decay, Lorentz transformations with angles

    Homework Statement I have a mother particle at rest, which decays to a daughter particle. The daughter has mass m, momentum p and energy E and is at an angle θ1. Now I have to assume that the daughter is emitted at an angle θ2, and the mother is moving along the x-axis with velocity βc. I need...
  5. C

    MHB Secant and Tangent Angles in Circles, finding an arc length.

    I got 138.17, but that isn't correct. I don't know how to do it, since the only way I thought, gave me the wrong answer. Can anyone help?
  6. B

    Why are the angles in rope equilibrium the same?

    Homework Statement Between two parallel walls we tighten a rope. One end of a rope is tied a little higher on the wall than the end on the opposite wall. On the rope we put a pulley with mass m which slides to equilibrium position. Homework EquationsThe Attempt at a Solution I assumed that in...
  7. A

    Special relativity - angles between fields

    Homework Statement In an electromagnetic filed, the elctric field ##\vec{E}## forms an angle ##\theta## with the magnetic field ##\vec{B}##, and ##\theta## is invariant for all inertial observers. Finding the value of ##\theta##. Homework Equations Tranformations of fields perpendicular to the...
  8. Physiona

    Angles involving trigonometric Ratios Worded Problem

    Homework Statement Triangle ABC is shown in the diagram below. A C AC = 3AB <BAC = 120° Respectively <BCA = Show that angle BCA can be written in the form...
  9. A

    Special relativity - Transformation of angles

    Homework Statement Let's have a three-particle decay of equal mass ##m##; in the CM frame the three particles have equal energy ##E## and they form angles of ##\frac{2\pi}{3}## between each other. Which is the angle between two of the three particles in the rest frame of the other one. (The...
  10. Physiona

    Find the Missing Angle in Triangle ABC: Use Arithmetic Sequence and Sine Rule

    QUESTION: The angles in triangle ABC form an increasing arithmetic sequence. The ratio of angles A:B:C can be written in the form 185:370:555 respectively. You are told that the total area of the triangle is 9 Length BC is Given the area of triangle ABC, work out the...
  11. lc99

    What Are the Forces Needed to Hold a Wheelbarrow at a 30∘ Angle?

    Homework Statement The wheelbarrow and its contents have a mass of m = 63 kg with a center of mass at G. Determine the normal reaction on the tire and the vertical force on each hand to hold it at θ = 30∘. Take a = 0.27 m , b = 0.43 m , c = 0.78 m and d = 0.10 m . (Figure 1) Homework...
  12. M

    MHB What is the reference angle for 60° and -60°?

    1. Find the reference angle given 60°. Let R = reference angle I decided to graph 60°. We are in Quadrant 1. R = 90° - 60° R = 30° Book's answer for R is 60°. 2. Find the reference angle given - 60°. I decided to graph - 60°. We are in Quadrant 4. R = -90° - (-60°) R = -90° + 60° R...
  13. lfdahl

    MHB A center of mass determined triangle: Find the angles of the triangle P_1P_2P_3

    Masses $m, 2m$ and $\sqrt{3}m$ are located at points $P_1, P_2$ and $P_3$ on a circle $C$ so that their center of mass coincides with the center of $C$. Find the angles of the triangle $P_1P_2P_3$.
  14. X

    B Measuring entangled particles along several angles

    Heya, I was wondering what happens when you measure the spin of particles along several different angles on an entangled pair. As far as I understand Bell's theorem, it basically says that if you first measure particle A in some angle, and then measure a particle B at some some angle, you'll...
  15. V

    Is the Left Angle of the CKM Unitarity Triangle Really Pi Minus Gamma?

    Homework Statement I want to proof for $$V_{us}V^{*}_{ub}+V_{cs}V^{*}_{cb}+V_{ts}V^{*}_{tb}=0$$ unitarity triangle that left angle is $$\pi-\gamma$$ (see below picture from my lecture notes). Homework Equations [/B] $$\gamma \approx - arg(V_{ub})$$ $$\beta_s \approx arg(V_{ts})+\pi$$...
  16. HastiM

    I Achromatic prism: Why subtract both angles of deflection?

    Hello, suppose we are given an achromatic prism consisting of two triangular prisms put together as it is shown on this webpage: http://www.schoolphysics.co.uk/age16-19/Optics/Refraction/text/Achromatic_prisms_and_lenses/index.html Imagine a light beam is send through the prism. My book claims...
  17. quasarLie

    How to Calculate Campbell Angles from Orbital Data?

    Homework Statement How can we calculate, the Campbell anglesknowing : Orbital period 4600 days the plane of the orbit makes an angle of 40 with the plane tangent to the celest vault The node line make an angle of 60 in the direct sense. starting from the node closest to the north, we find an...
  18. sparkie

    Using reference angles to evaluate trig function

    Mod note: Moved from a Homework section, as this is more of a conceptual question than an actual homework problem. I can't really memorize the unit circle, but I do remember my instructor teaching us how to use reference angles to evaluate any trig function without needing the unit circle. I was...
  19. MrGenetic

    Ramachandran plot torsion angles

    Can torsion angles were affected by repulsive effect of aminoacid interactions between side chains? Can torsion angles were affected by hydrophilic or hydrophilic interactions between side chains? I know that protein levels were affected by them but torsion angles is suspicious for me
  20. V

    B Two waves moving at right angles go in circles?

    ylet x = Asinx, y = Acosx, apparently x^2 + y^2 = A^2 so this combination goes in circles. wot? creating waves in a pool 90 degrees off and out of phase by 90 will make it move in circles? I'm skeptical, anyone have a video of an experiment that demonstrates this?
  21. riveay

    Euler angles in torque free precession of a symmetric top

    Is calculating the Euler angles analitically possible? I am trying to obtain the angles to transform the body-fixed reference frame to the inertial reference frame. I can get them without problems with numerical methods. But I would to validate them analitically, if possible. I followed the...
  22. J

    Geometry: Solve for angles of a triangle w/line intersecting

    My mother's boyfriend's son who is in 6th grade asked me a question about the math they are learning. I thought it wouldn't be too bad but I cannot for the life of me figure it out. A solution would be greatly appreciated. 1. Homework Statement https://postimg.org/image/1tsa4v4t8r/ Homework...
  23. M

    MHB Solving Acute Triangle Angles Given $A,B,C$ & Equations

    Given that $A,B,C$ be angles in an acute triangle. If $(5+4\cos A)(5-4\cos B)=9$ and $(13-12\cos B)(13-12\cos C)=25$ find $cos(A+C)$. I know $A+B+C=180^{o}$ and $\cos B=-\cos(A+C)$ and what next?
  24. M

    Find the tension in the cable and the force the ramp exerts on the tires

    Homework Statement A 5000 kg car rests on a 32° slanted ramp attached to a trailer. Only a cable running from the trailer to the car prevents the car from rolling off the ramp (the car's transmission is in neutral and its brakes are off). Find the tension in the cable and the force that the...
  25. A

    Spring angles at static equilibrium on application of force

    Homework Statement Two linear springs with stiffness Kh, Kv are attached to a single mass m at right angle to each other, i.e; one of the spring(Kh) is in the horizontal direction(x-axis) and the other(Kv) is in the vertical direction(y-axis). A constant force F is being applied to the mass...
  26. G

    Vectors and Angles in Helicopter Flight

    Homework Statement Bob has a helicopter and from the launch pad he flies the following path. First he travels from the launch pad a distance of 17 kilometers at heading of 63 degrees East of South. Then he flies 45 kilometers heading 73 degrees West of North. After this he flies 34 kilometers...
  27. J

    I Calculate object distance by using just the parallax angles

    I have a simple paper with parallel grid lines and I know the height of the observer from the ground level. Now when I snap the picture with my camera, the effect i get is what is seen in the image below. Even if the lines are parallel, the perception is that they converge in the middle. When...
  28. J

    I How to Prove the Solid Angle Formula for Vector Fields?

    Hello, I would like to ask you for hints to proof this: \int^4 pi \omega \omega \,d\omega =%fraction{4}{3} \pi where omega is vector. Do you have any hints for me? (Not seeing for solution, just hints).
  29. karush

    MHB S4.13.t.71 Angles of triangle PQR

    232.q1.4a sketch the region of integration $\displaystyle\int_{-2}^{2}\int_{\sqrt{4y^2}}^{4-y^2} f(x,y)\,dx \,dy$ this is what i did with desmos don't know how to shade the integrated area if the it is even correct😎
  30. kolleamm

    I Arm reaching algorithm determine angles

    I'm trying to find an algorithm for extending an arm as close as possible to an object. There's two bones the upper arm bone and the lower arm bone, and three points : shoulder , elbow, hand How can I figure out the closest possible configuration towards a fourth point which is the object it's...
  31. karush

    MHB S4.13.t.71 angles of triangle PQR

    $\tiny{s4.13.t.71}$ $\textsf{For the given points $P(0,-1,2), Q(4,4,1), R(-4,4,6)$}$ $\textsf{Find the approximate measurements of the angles of $\triangle$ PQR. }$ $\textit{Ok, presume its get vectors first then use Dot Product...}$ $\textit{First find vectors $\vec{PQ},\vec{QR},$ and...
  32. Zafa Pi

    I Can a tetrahedron have all dihedral angles rational?

    At each edge of a tetrahedron the 2 common faces form a dihedral angle. Can each of these 6 angles be rational multiples of pi?
  33. B

    Dynamics ramp and friction. Finding angle?

    Homework Statement A 3.0 kg block is released from the top of a rough ramp of length 2.0m and accelerates down the ramp at 1.6m/s^2. If a force of kinetic friction of 10 N acts on the block, what is the angle of the ramp. Homework Equations Fnet=ma ff=(mu? I don't have that symbol HAHA) muFn...
  34. T

    Predicting lift on an Aerofoil with varying Angles of Attack

    I am conducting a school based EEI and have found issues in predicting lift on an aerofoil with respect to angle of attack.I understand the formula for lift is L = (1/2) d v2 s CL. I also understand there are many confusing variations to the calculation for the lift coefficient but i am yet to...
  35. B

    Help (: adding vectors components.... angles, drawing.

    Homework Statement A ship traveling 55 degrees [W of N] is 65km farther north after 3.0h. What is the ship's velocity. Homework Equations sin, cos, tan? The Attempt at a Solution I know that Vground= Vair + Vwind, and that Vground = Vboat + Vcurrent, but I'm not sure if that is even relevant...
  36. J

    Will the Man Use His Right Hand in Any of the Mirror Images?

    Homework Statement Homework EquationsThe Attempt at a Solution [/B] There will be 3 images formed .If the man is standing symmetrically then first image will be behind mirror M1 .2nd will be behind M2 . 3rd will lie on the angle bisector of the mirrors .This image will be behind both M1 and...
  37. e2m2a

    What is the formula for tension at various angles in a constrained mass system?

    [No template as this thread was moved to Homework from the general physics forum] I have been struggling with this problem for years and never have found an answer to it anywhere on the web or in textbooks. And I can’t derive the formula for it. Suppose we have a mass designated as ##m_2##...
  38. B

    Speed of pendulum at certain angles

    I'm having no problem finding the maximum speed of a pendulum but I'm not sure when I move its start point and measure point. I would like to know the speed of a pendulum at 30 degrees that has been dropped at 140 Degrees. I'm just giving some numbers to explain that it is above the horizontal...
  39. Jamison Lahman

    What is the correct angle between two vectors?

    Homework Statement From Analytical Mechanics by Grant R. Fowles & George L. Cassiday. Only problem I am having is with part d. Homework Equations ##A\cdot B = A_xB_x+A_yB_y+A_zB_z## ##sin(\theta) = \frac{|A\times B|}{AB}## The Attempt at a Solution I did it by hand but also ran the following...
  40. H

    How to find the angles of a triangle in a semicircle?

    Homework Statement Homework Equations d(y)/d(x) --> max area area of triangle = 1/2 . base . height The Attempt at a Solution for number (2) [/B] x^2 + y^2 = r^2 --> circle equation base = 2R, height = y Area = 1/2 . 2R . y area = 1/2 . 4. √ (r^2 - x^2) area now is half of max = 2, so...
  41. Vital

    Is there an algorithms to determine correct angles

    Homework Statement Hello! I am struggling with plotting polar graphs manually (without any help of the calculator). My main unresolved issue is with finding correct values of theta in a given range. For example, I have an equation: $r = cos(5\theta)$ Homework Equations and I know that the...
  42. P

    A Parameterizing the 3-Sphere: 3 Angles?

    How would one parameterize the three-sphere? Would three angles work: latitude, longitude and something?
  43. Bunny-chan

    Dynamics problem about two-dimensional tug-of-war

    Homework Statement In a two-dimensional tug-of-war, Alex, Betty, and Charles pull horizontally on an automobile tire at the angles shown in the picture. The tire remains stationary in spite of the three pulls. Alex pulls with force \vec{F_A} of magnitude 220~N, and Charles pulls with force...
  44. V

    Bode phase plots and initial angles of transfer functions

    Hello everyone. So I have a test coming up and I am struggling with the concept of figure out what the initial phase or angle of a transfer function is. For instance, consider the following transfer function: L(s) = 4/s(.4s+1)(s+2) So the initial angle for L(s) is -90 degrees. Is there a...
  45. Const@ntine

    B How do I determine angle equality in this graph?

    Okay, this might be a tad silly, but I cam across this graph/picture i my physics textbook, and for the life of me I can't figure out how to connect the two angles. Here, have a look: It's not a big part of what the paragraph is about, so in theory I could just skip it, but it's been...
  46. Bunny-chan

    Projectiles launched at complementary angles

    Homework Statement a) Show that for a given velocity V_0 a projectile can reach the same range R from two different angles \theta = 45 + \delta and \theta = 45 - \delta, as long as R doesn't go over the maximum range R_{max} = \frac{V_0^2}{g}. Calculate \delta in function of V_0 and R. b)...
  47. sunzone

    B Calculate angles from infomation given

    Hello :) I have a math problem, where I am trying to calculate Q1 (Q2 & Q3) with the info given on the image. I keep telling myself that i need Q2 or/and Q3 to find Q1, but i can't find a formula that i can use I've drawn it, and found out that Q1 is 10mm, but i can't prove it with math...
  48. Superman123

    Calculating Angle to Shoot Sword Over Wall for UT - 65 Characters

    Homework Statement UT has jumped over a wall and unfortunately for her, she forgot to bring her sword. Her friend SS decided to shoot the sword to her with a bow. He can bend a bow and arrow so that it gets a potential energy of 179 Nm. It seemed that Ut landed 9 meters behind the wall; a...
  49. JLD Co

    Solving a torque equation with two force angles

    I'm comparing the torque developed by two different engine concepts. One is a new fandangled concept being built that lends itself to a simple torque equation F x r x sine theta (Force, radial vector of the crank, angle of Force) because it has only one angle of Force being applied to the...
  50. V

    How Does Earth's Magnetic Field Combine with a Nearby Current-Carrying Wire?

    A long horizontal wire carries 22.0A of current due north. What is the net magnetic field 20.0 cm due west of the wire if the Earth's field there points downward, 40 degrees below the horizontal, and has magnitude 5.0 E-5 T? My approach: 1. Drew north to the right and the wire lying flat, with...
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