Angle Definition and 1000 Threads

  1. J

    Downwash reducing angle of attack of a wing?

    There is theory in aerodynamics for 3D wing (finite span) that say : quoted Douglas Mclean book: "wing is flying through air that is already moving generally downward between wingtips.Thus the wing can be thought of as flying downdraft, or downwash, of its own making. 3D downwash can thus be...
  2. Spocktastic

    What is the Correct Angle for Tension Force in Arm Mechanics?

    I already solved for part a, setting the sum of the Torques of the arms and deltoid equal to 0 and subbing in values which lead to a tension force of 870N in the deltoid. For part b, I remembered the law of static equilibrium, so the summation x and y components of all the forces in the system...
  3. J

    A Why does the free end refraction occur after Brewster's angle in TM?

    Thanks for reading my question, and i’m really sorry about my poor english. What i am wondering about is why does the free end occur after the incidence angle overcome the Brewster angle in TM wave? (The ray incident from vacuum to glass(dense medium)) i tried to interpret this phenomenon with...
  4. S

    Maximum angle reached by a cube placed inside a spinning cylinder

    I am trying to solve a problem where we have to find the maximum angle before a cube starts sliding when said cube is placed inside a spinning hollow cylinder (the cylinder is placed horizontally). The radius of the cylinder is 0.4 m, the coefficient of static friction between the cube and the...
  5. Philip Koeck

    A Fast electrons passing a beam of slow electrons at a right angle

    I'm wondering what happens when fast electrons (100 - 300 keV) interact with a beam (diameter 1 to 10 μm) of slower electrons (1 to 10 keV), which is at right angles to the trajectories of the fast electrons. The beam of slower electrons is relatively dense with 1 to 10 electrons per μm line...
  6. Leo Liu

    Why doesn't aircraft weight affect descent angle in a gliding flight

    It's a homework question, but I feel like it fits better in this forum. The solution fails to convince me because C_D and C_L can be both written in terms of weight: $$C_L=\frac{2W}{\rho v^2 S}$$ $$C_D=C_{D0}+k_1 C_L(W)+K_2 C_L(W)^2$$ Question: Solution: Any insight will be appreciated.
  7. J

    Ideal car rear roofline angle and shape for low drag?

    What is ideal rear roofline(rear window and trunk) angle and shape(straight line, curve ..etc) for lower drag? Keep in mind if you increase angle, you reduce butt area / wake, but induce low pressure at rear window/trunk , if you decrease angle you increase butt/wake but increase pressure at...
  8. A

    B Understanding the Doppler Effect at an Angle

    hello everyone How is the sound Doppler effect formula in the case where the movement of the source and the observer is at an angle?
  9. G

    I What is the angle of the Sun on June 21 & Dec 21 at US Zip Code 37129?

    What is angle of Sun June 21 & Dec 21 at zip code 37129. I need lowest angle & highest angle and probably angle of sun about Feb 20. Google word search shows nothing. I am probably need using correct word search to find what I want. Several years ago I accidently found a calendar that showed...
  10. FEAnalyst

    Gear teeth force from the rotation angle

    Hi, in books about machine design fundamentals, one may easily find the formulas for forces acting on the teeth of paired spur gears. They require torque as input. For example, for the tangential force: $$F=\frac{2T}{d}$$ where: ##T## - torque applied to the driven gear, ##d## - pitch diameter...
  11. jevans123

    Pulling a crate across the floor with a rope at an angle

    I drew out a motion diagram and used 115N sin(26.7 degrees) = 51.7 N but It turns out to be wrong.
  12. Ahmed1029

    I What's the definition of angle in a curved space embedded in a higher Eucledian space?

    I don't want to post this in a math forum because it's very basic and I just want a straightforward answer, not something math heavy . What's the definition of angle in a cuved space embedded in a higher eucledian space? Like when I have a spherical surface in 3d eucledian space and want to work...
  13. Jan Berkhout

    Calculate the best angle for maximum light dispersion through a medium

    I first thought that the angle would have to be maximum when it is closest to the critical angle for total internal reflection. From my lectures the equation for the critical angle is ##\theta _1>\ sin ^{-1} \left( \frac {n_2} {n_1} \right),## so as ##n_2 = 1##, we have ##\theta _1=\sin...
  14. chwala

    How Do You Calculate Angles AEC and ADC in Geometry?

    Question; Text Solution; My reasoning; ##∠ABC= 180^0 -(32^0+60^0)## =##88^0## ##∠ABC=∠ACF=88^0## (Alternate segment theorem). ##∠EBC=92^0## i.e angles lying on a straight line and ##∠BCE=180^0 -(88^0+60^0)=32^0## therefore; ##∠BEC=180^0 -(32^0+92^0)=56^0##...
  15. babaliaris

    For a Pendulum: Knowing Acceleration Find Maximum Angle

    PS: By the way today I had exams in Physics and this problem was the first one I had to solve :p (unlucky) The question was to find the maximum angle θ that the pendulum can reach if we know that the magnitude of the acceleration is the same when the mass is located in the highest and the lowest...
  16. D

    Designing a spiral with a certain angle relative to movement direction

    I have a disk traveling on the inner blue track (let's say the blue part is the center of the disk). I want to push the disk outside (as the disk is traveling in a circle) to the outer track. The black part is the wall separating the tracks To that end, I've made some calculations, but I have...
  17. tbn032

    B Confusion about the angle between two vectors in a cross product

    The magnitude of cross product is defined of vector A⃗ and B⃗ as |A⃗×B⃗|=|A⃗||B⃗|sinθ where θ is defined as the angle between the two vector and 0≤θ≤π.the domain of θ is defined 0≤θ≤π so that the value of sinθ remains positive and thus the value of the magnitude |A⃗||B⃗|sinθ also remain positive...
  18. X

    I Why do droplets of condensation run at an angle on a plastic sheet?

    I think the picture says it all! As the droplets of condensation reached a certain size they begin to run down the plastic sheet, but rather than just running straight down, they veer off to the left or right. Most of the tracks are at fairly much parallel, with some exceptions, and the pattern...
  19. Benjies

    Subsonic airbreathing engines and inlet blade angle

    Hello! My background in propulsion is extremely lackluster with airbreathing engines, so any help is appreciated with the following questions. I understand blade pitch is highly variable for turbofans which operate near the speed of sound, to avoid any localities on the blades reaching the speed...
  20. M

    MHB Prove Angle of Diagonals in Quadrilateral is Degrees

    Two angles of a square with side protrude beyond a strip of width with parallel edges. The sides of the square intersect the edges of the strip at four points. Prove that the diagonals of the quadrilateral whose vertices are these points intersect at an angle of degrees.
  21. S

    Initial velocity and angle when a ball is kicked over a 3m fence

    Hello there, I don't understand what I'm doing wrong I don't get the correct answer, but have done the same analysis 3x already and still get the same... Some input would be appreciated thanks in advance. Note: y-axis is upwards and x-axis is to the right. 3 unkowns i.e. 3eqs. ##x = x_0 +...
  22. M

    MHB Find the angle in the triangle

    I've tried: BC || EF How to find angle GDC? I think GDC=7x but why? I have an answer but how to solve this?
  23. S

    Calculating Max Tension, Final Angle for Swinging on Rope Over Lake

    Please tell me if I need to post my solution for this.., but I just have a question more or less 'conceptual' question about (c). so I know that from Newton's 2nd law for centripetal acceleration --> ##F_{rope} - mgcos(\theta) = ma_n## where ##a_n = \frac {v^2}{R}## such that where the normal...
  24. S

    The angle at which a skier will leave the sphere

    Back here again.. but I am sorry guys, only the parameters are on my paper so wouldn't be of much help to show. I basically have no clue on how to start solving this problem at all. I stopped yesterday and let it sit overnight but still have no clue on how to approach the problem basically...
  25. dejavu333

    Projectile Launch Angle: What Could Be Causing My Arccos Computation Problem?

    if the target is lower than me, the formula is below, but if it's higher as in the task, a whole different formula is required I think. a = 9.8 * distance^2 / velocity^2 phi = Arctan(distance / height_diff) angle_if_elevation = ( Arccos((a - height_diff) / Sqroot(height_diff^2) + distance^2)) +...
  26. G

    Find v_1 for projectile using start position, final position and angle

    I have attempted the problem a few times, and have posted my work below. I thought to check my work using ## v_x t = v_1 \times \cos\theta \times t = \Delta x## to see if I get back expected results, and I did for the horizontal motion (the substitutions are from the numbered steps below): ##...
  27. N

    I Lens angle of coverage/image circle

    Hello, I was wondering what parameters determine the angle of coverage/size of the image circle of a lens. For example, for a fixed focal length, aperture and flange focal distance of a camera, what can a lens designer do to change the size of the image circle. I'd also like to know how the...
  28. LCSphysicist

    Bragg angle with an inclined plane through a square lattice

    Suppose a square lattice. The planes are such as the image below: I light wave incides perpendicular to the square lattice. The first maximum occurs for bragg angle (angle with the plane (griding angle) as ##\theta_B = 30°## (blue/green), green/blue in the figure). The angle that the...
  29. P

    Calculate tilt angle of a bar lifted via two ropes on fixed points

    Summary: How to calculate the equilibrium angle of a bar that is lifted on its two ends with ropes attached to fixed lifting points? Hello and good day all, First of all I would like to apologize in advance for my english, I am not a native speaker so some grammar errors may be left. My...
  30. gregh

    Find the wingspan and sweep angle of a V-tail

    Hello guys this is my fisrt post on this forum ; I can't find anywhere how to calculate the aspect ratio and sweep angle of a V-tail. in my project I have a fixed wing uav with a normal tail that has Har = 3.1 and a Var = 1.7. following this site: "...
  31. S

    I Derive the probability of spin at arbitrary angle is cos( )

    From Dr. Leonard Susskind's Stanford Lecture: Quantum Entanglement, Lecture 4, he sets up a "given particle is spin up along n (arbitrary direction) and discusses : what is probability we measure up along another arbitrary m directionHe does all of the setup, - calculates the eigenvectors and...
  32. Ranku

    I Unitarity Triangle CP Violation Angle β & θ

    Unitarity Triangle containing angle β describes CP violation in the weak interaction. If there is CP violation in the strong interaction, is it also described by a Unitarity Triangle containing the CP violating angle θ?
  33. LCSphysicist

    Preservation of the angle between two vectors

    Homework Statement:: . Relevant Equations:: . Generally, when we talk about preservation of angle between two vectors, we talk about conformal transformation. But what is confusing me is, shouldn't any general transformation of coordinates preserve the angle between two vectors? What i mean...
  34. P

    MATLAB Phasor diagram - how to check angle in matlab?

    I have a problem with checking angle in phasor diagram. I print my phasor diagram and I don't know how to check angle in window. Have somebody any idea how to search that? Maybe it is not possible and I need to add function in my MATLAB code to get result.
  35. F

    B Compound Angle Formula: Solving Double Angle Equations

    Hi, I am confused about how to handle the double angle formula. For example, sin(19pi/12)= sin(9pi/12+10pi/12) but there can be many other options too. like sin(18pi/12+pi/12) or sin(15pi/12+4pi/12)..every time I am getting different answers. Can anyone please how find the right one? Thanks
  36. safetnezic

    I How to determine the sign of an angle in Bio Savar's law?

    Hello everyone. I use Bio Savar's law to determine the intensity of the magnetic induction vector. I use this formula R is distance of wire from point in which I calculate intensity of the magnetic induction. How can I known which angle is positive and which angle is negative from this two...
  37. H

    I What will the angle of a boat with an outboard motor be?

    I want to calculate the angle of a wooden boat at rest in salt water, with a 55 lb outboard motor mounted on the transom + 3 gallons of gasoline (18 lbs) + 2 adults weighing about 150 lbs each. So just figure a total weight at the back end of the boat being 55 + 18 + 300 = 373 lbs. The boat...
  38. A

    MHB Formula to find arc radius using arc length, chord length, and/or segment angle

    I'm attempting to write some code using the Ruby programming language that will give me the radius of an arc but the only pieces of information I have to work with are the arc length (L), the chord length (C), and the circular segment angle in degrees (A): I'm hoping someone can show me how to...
  39. vibha_ganji

    Maximum Deflection Angle In Elastic Collision

    I started by writing the equation v1i + v1f = 2v and then drawing a triangle with v1i, v1f, and 2v as the three sides. Then I used the Law of Cosines to solve for cos theta but this did not lead to a solution. Could I have a hint on how to begin? Thank you!
  40. H

    Finding the angle at the apex of a rhomb with incoming linear wave

    Hi, Since I'm dealing with a rhombus, the angle at the bottom(A) and top(A) are the same. Thus, I only have to find the angle at the bottom since the incoming beam is already perpendicular to the side of the rhombus. Since the incoming beam is perpendicular to the side ##\theta_I = \theta_T =...
  41. karush

    MHB What is the measure of angle KPM?

    ray $\overline{PK}$ bisects the meausre of $\angle{LPM}$ is $11x^o$ and the measure of $\angle{LPK}$ is $(4x+18)^o$ What is the measure of $\angle{KPM}$ a. $12^o\quad$ b, $28\dfrac{2}{7}^o\quad$ c. $42^o\quad$ d. $61\dfrac{1}{5}^o\quad$ e. $66^o$ ok I think this could be done by...
  42. ChichoRD

    Creating an Enemy with 2D Linear Movement: Calculating Projectile Angle

    Hi, I am a game developer and recently found myself in a situation where I wanted to create an enemy that shoots at you given a set of variables. The game takes place in a top down view so there is no need for gravity acceleration, just 2d linear constant movement. The question to answer is...
  43. T

    MHB Find this unknown angle in the triangle

    Find the unknown angle in the triangle. It is quite an interesting task. I will put a trigonometric solution, Mabra I wonder how it opens geometrically. Help someone
  44. dirb

    Calculating Angle & Speed to Reach Planet's Moon from Station Orbit

    A station is orbiting a planet at a distance R1, a moon is orbiting the planet at distance R2 with the period T. The planet itself has a radius rp and a mass mp. We know that when an object adds its velocity at a point in the orbit, the height of the opposite orbit will increase. Determine the...
  45. B

    Correct Angle for FSW in Fabry-Perot Interferometer

    Sorry for the lack of formatting, I'm in a rush to write this before I go pick someone up from work. My question is what is theta1? Is it 45 degrees because that's the angle the light hits the boundary of the plate to the n1 medium? Or is it 0? It seems like it should be 45 but there's an...
  46. M

    Helix Angle or Pitch Angle for this Solenoid carring Current?

    I honestly have such a dumb question- it says “a pitch angle” but cannot find that in relation to a helix. It is not defined in the textbook. Looking on google I found a helix angle, but is that different than the pitch angle? Can anyone draw me a picture of where the pitch angle is? I assumed...
  47. S

    How to find the angle where the required pull is minimum?

    Can I get some help on how I'd do that? I would parametrize the angle in the equation of where T = 188N and then take the derivative. And then, what should I do then? it's not T' = 0 and I didn't have maxima minima vals in calc so yeah. Thanks in advance.
  48. G

    To find the angle between the ground and rods in limiting friction

    Could I please ask for help with the following: Here's my diagram: The forces at the hinge (green) are internal forces. For the whole system resolving vertically gives: R1 + R2 = 4W and horizontally gives: F1 = F2 For the rod of weight 3W only, taking moments about B gives: F1 * L *...
  49. S

    Max initial angle so that the projectile range keeps increasing

    Can I get a hint on how to start with this problem ? Thanks in advance I can't really think of anything...
  50. A

    Max Angle of Mass on Incline Surface

    Hello, I've worked through the free-body diagram to compute the answer: tan(𝜃) = 0.67 𝜃 = arctan(0.67) = 33.822... The answer is supposed to be approximately 42. Yet, tan(42) is not 0.67, is the suggested answer wrong?
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