Angles Definition and 911 Threads

  1. D

    Prism Optics Range of Refraction Angles

    Homework Statement Equilateral triangle prism (angles all 60 degrees) made of crown glass. Index of refraction ranges from 1.486 for longest visible wavelengths to 1.556 for the shortest. What is range of refraction angles for the light transmitted into air through the right side of the...
  2. R

    Blade angles, Reaction, Diffusion

    I'm really confused about an in class example my professor did to show how to obtain the hub and tip degrees of reaction of a free-vortex compressor stage and the diffusion factor for the rotor tip Given: \frac{\Delta P_t}{\rho {W_0}^2}=0.9 \frac{r_t}{r_h}=2.646 ^{\circ}R_m=0.5...
  3. T

    Lift from airfoils, decrease lift as a result of curved shape at large angles?

    Hi, in my point of view lift is created as a result of two pressures, the static and the dynamic. The dynamic pressure is the dominating creator of lift at large angles of attack. For example a flat plane at 45 degrees will create lift. The static pressure is the dominating creator of...
  4. R

    Doppler Shift at Right Angles Confusion

    Hi, I'm reading "The First Three Minutes" by Steven Weinberg And am confused about this paragraph... "Astronomers are able to measure the motion of a luminous body in a direction directly along the line of sight much more accurately than they can measure its motion at right angles to...
  5. M

    What is the angle between vectors A and B?

    Homework Statement Two vectors A and B have magnitude A = 2.99 and B = 3.10. Their vector product is A X B = -4.98 k + 2.08 i . What is the angle between A and B? Homework Equations C= ABsinθ C=A X B The Attempt at a Solution θ= arcsin C/(⎮A⎮⎮B⎮) so i found the magnitude...
  6. O

    Linear Approximation of Angles

    Homework Statement A player located 18.1 ft from a basket launches a successful jump shot from a height of 10 ft (level with the rim of the basket), at an angle Θ = 34 degrees and initial velocity of v = 25 ft/s.A. Show that the distance s of the shot changes by approximately 0.255∆Θ ft if the...
  7. P

    Force and acceleration given position equations. Find magnitude and angles

    Homework Statement A 0.42 kg particle moves in an xy plane according to x(t) = - 19 + 2 t - 2 t3 and y(t) = 25 + 8 t - 7 t2, with x and y in meters and t in seconds. At t = 0.6 s, what are (a) the magnitude and (b) the angle (within (-180°, 180°] interval relative to the positive direction of...
  8. A

    Raising Complex Numbers to Powers of Angles - What Happens?

    is there anyone who can tell me what happen when i raise a complex number to the power of an angle in rad? for example, what is the result of (i)^1rad?
  9. G

    Drawing Mhor's Circles: Orientation Angles on One Axes

    Dear all, i want to draw the Mhor's circles for various orientation agles on a same axes
  10. B

    How Do I Solve Angle Problems in Physics?

    Attached are 3 problems that we were never shown in class on how to do it. I have a test in 3 days and need to figure this out, and no more class time. Question 10 12 and 13. We NEVER did anything with angles in it. And nothing like pulleys this way either. As for 12 I see you have to do...
  11. S

    Kicking a Field Goal: Calculating Elevation Angles

    Homework Statement A football kicker can give the ball an initial speed of 30 m/s. What are the (a) least and (b) greatest elevation angles at which he can kick the ball to score a field goal from a point 48 m in front of goalposts whose horizontal bar is 3.44 m above the ground? Homework...
  12. C

    How Do I Convert Angles into Velocities? - Math Problem Help

    Hi PF, I would really appreciate it if you can help me through this math problem. I have 3 angles: x, y, and z. I need to convert them into x,y,z velocities (say 5 m/s) in that direction. I have no idea where to even start. Did a lot of searching to no avail :(
  13. T

    Problem with angles and differentiation

    Homework Statement A "big screen" AB of height L is placed at a height h above a point C on the ground as shown (in the attachment). A person wishes to sit on the ground at a point D in order to watch a video on the big screen. She wishes to sit at a horizontal distance x away from C which...
  14. M

    Complimentary Angles: Understand Why sin(90-theta) = cos theta

    Homework Statement It bascially says when the sum of two angles are 90 deg they are complimentary... Then it goes on saying sin(90-theta) = cos theta and so on... I understand the concept such as if sin(30) = cos(60) But the book doesn't explain why it works.. it just says if two compl...
  15. K

    Solid Angles 101: A Crash Course

    Hey I'm having a hard time wrapping my head around the concept of solid angles and finding the solid angle of any area on the surface of a sphere I'm basically asking for a crash course none of my textbooks explain it well at all
  16. O

    Solving Speeds of Objects after Collision with Two Angles

    Homework Statement A 0.17kg cue ball is moving at 4.0 m/s when it strikes a 0.16 kg stationary object ball. After the collision, the cue ball moves 60 degrees to the left of its original direction while the object ball moves 30 degrees to the right of the cue ball's original path. Determine the...
  17. M

    What Angles Will Hit a 91.4m Target with a 596 m/s Bullet?

    Homework Statement The drawing shows an exaggerated view of a rifle that has been ‘sighted in' for a 91.4-meter target. If the muzzle speed of the bullet is v0 = 596 m/s, there are the two possible angles θ1 and θ2 between the rifle barrel and the horizontal such that the bullet will hit the...
  18. D

    How Do You Calculate Cylinder Rotation Using Laser Reflection?

    Homework Statement You're helping with an experiment in which a vertical cylinder will rotate about its axis by a very small angle. You need to devise a way to measure this angle. You decide to use what is called an optical lever. You begin by mounting a small mirror on top of the cylinder. A...
  19. T

    Upper Surface Transition at Negative Angles of Attack

    I'm trying to validate some experimental data on a NACA 643-418 wing section from XFoil. Below are some basis data, Number of panels around the airfoil - 43 Mach number - 0.0487 Reynold number - 1107872 Velocity - 16.67 (not important) During the analysis I have set the upper surface...
  20. Q

    Solid angles and particle velocities

    This should be a simple question, but I haven't found a clear explanation anywhere yet. Suppose that there are a bunch of particles in a gas, with their velocities "uniformly distributed over solid angles", and I want to find out what fraction of particles are traveling with velocities in a...
  21. C

    Trying to prove two angles are congruen to each other

    Homework Statement [PLAIN]http://img831.imageshack.us/img831/2589/88722757.jpg Using only the fact that the sum of the interior angles of a triangle is 180, how would I show that a = a* and b = b*? Homework Equations The Attempt at a Solution In my diagram, there are 2...
  22. 1

    Reference Angles: Find the Angle of $\frac{7\pi}{6}$

    Homework Statement Find the reference angle of - \frac{7\pi}{6} Homework Equations - The Attempt at a Solution I can tell you right now, that the answer is pi / 6. My method would be to sketch the angle, find out at which point the appropriate x axis-coordinate will be used...
  23. M

    Understanding 45-45-90 Degrees Angles

    Homework Statement Say I am dealing with a 45-45-90 deg angle then sin(45 deg) = 1/(2)^(1/2) What exactly is the value of 1/(2)^(1/2) referring to? is is the measure of a side or what? Homework Equations The Attempt at a Solution
  24. B

    Magnitude and coordinate direction angles of the resultant force.

    Problem is here http://engineeringhomework.net/statics/FG02_32-03UNP62.JPG Determine the magnitude and coordinate direction angles of the resultant force. I don't know where to start on this one.
  25. S

    Need Help With Quadrilateral Calculations: LN and KM Angles

    Hey guys, not touched any mathematics in almost 5 years and I am just getting back into it, been going well so far but hit a hurdle with this, I presume its some gaps in my knowledge. So been at this for about an hour, got the first one, no clue on the second, can anyone offer assistance?K(-2...
  26. S

    Finding Polar & Azimuthal Angles of 3D Vector

    Hi, Can anybody help me to find the polar angle and the azimuthal angle of a given 3D vector? Say we know the ordinates of the two point A(x1,y1,z1) and B(x2,y2,z2). So the question is find angles (Theta and Phi) of the vector AB. Any suggestion would be really appreciated. Thanks. Susantha
  27. D

    What Angles Affect the Vector Components of a Weight on an Inclined Plane?

    Homework Statement The weight of a book sliding down a frictionless inclined plane can be broken into two vector components: one acting parallel to the plane, and the other acting perpendicular to the plane. (a) At what angle is the components equal? (b) At what angle is the component...
  28. A

    Momemuntum of bodies at right angles

    Homework Statement Hi Can someone help with this problem. 2 particles of mass 30g and 40g respectively both travel at a speed of 35m/s in directions at right angles. The 2 particles collide and stick together. Calculate their speed after impact. Homework Equations MaVa + MbVb =(Ma +...
  29. F

    What Are the First Five Bragg Scattering Angles for Cu X-ray Analysis?

    Homework Statement A thin polycrystalline film of Cu, with lattice parameter of 0.361 nm, is irradiated with X-rays with wavelength of 0.154 nm. Calculate the first 5 bragg scattering angles for which X-rays may be detected.Homework Equations 2dsin(\theta) = n\lambda Bragg condition for...
  30. P

    Polar Coordinate Symmetry with Double Angles

    Homework Statement Given the equation r²=25sin2Θ Asked to find symmetry with respect to line Θ = pi/2 Homework Equations w.r.t. Θ = pi/2: (r,Θ) - (r, pi-Θ) and (r, Θ) - (-r,-Θ) The Attempt at a Solution For the first case, I plugged in (pi-Θ) for Θ, but I'm confused about what to do...
  31. T

    What is the net torque given the angles of applied forces

    1. STATEMENT Calculate the net torque about a fixed pointfor 2 different forces given the angles of the applied forces. 2. MY QUESTION what is the net force, meaning how do i fint it? and what do i do wit the information given? Do i use T=r x F...
  32. M

    Physics question: Finding 2 angles with given tensions and mass

    Homework Statement Suppose the traffic light (1.00 x 10^2 N) is hung so that the tensions T1 and T2 are both equal to 80.0 N. Find the new angles they make with respect to the x axis. (By symmetry, these angles will be the same.) Homework Equations Fx = 0 = -T1 cos theta + T2 cos theta Fy...
  33. A

    Using double angles to find value of

    Homework Statement Homework Equations The Attempt at a Solution I know the following: sin^2x = 8/9 the hyp. is 9, the "y" value is 8. Therefore, the "x" value has to be \sqrt{17} What is the next step?
  34. J

    Interior angles of a regular polygon

    The number of sides of two regular polygons are in the ratio 5:4 and the difference between their interior angles is 6 degrees.Find the number of sides of the two polygons. I forgot the relation between interior angles and the number of sides of a regular polygon.Can anyone help me to figure...
  35. N

    Why are these two angles congruent?

    Why does angle LAB = angle ACB? line AL is tangent to the circle at A Triangle ABC is inscribed in the circle http://img13.imageshack.us/img13/9553/tricircle.png Uploaded with ImageShack.us
  36. L

    Forces, Vectors, Angles, Magnitude, CONFUSED

    Homework Statement Consider four vectors ~ F1, ~ F2, ~ F3, and ~ F4 with magnitudes F1 = 59 N, F2 = 29 N, F3 = 11 N, and F4 = 60 N, θ1 = 150 ◦, θ2 = −150 ◦, θ3 = 23◦, and θ4 = −56◦, measured from the positive x-axis with counterclockwise positive. What is the magnitude of the resultant...
  37. MysticDude

    Increasing F-A-F Bond Angles: OF2, NF3, CF4, BeF3, BeF2

    Homework Statement Another chemistry question :D Arrange the following AFn species in order of increasing F-A-F bond angles: BeF3, BeF2, CF44, NF3, and OF2.Homework Equations The Attempt at a Solution Ok so I'm thinking that it would be OF2 first because it's bent and both of the lone pairs...
  38. R

    Angles between 2 points along a varied path

    I am writing a program that uses Snell's Law for refraction of light through two interfaces and I've encountered a problem representing the geometry symbolically. I could determine the values numerically but I don't want the overhead as it would have to be called up to 1E7 times. The...
  39. H

    Correcting accelerometer mounting angles

    Hi all! I'm working on a system that uses an accelerometer to measure pitch. I know how I can calculate the pitch angle from the accelerometer readings, but I've another problem. At the start I never know how the accelerometer is mounted. So normally on at the start the accelerometer...
  40. M

    Projectile Motion: Negative Launch Angles?

    Hello everyone! This is my first post, and I regret that it has to be a question that is so elementary. The Problem: I am in an introductory engineering course in which we were divided into teams and told to construct a catapult. Rather than follow design requirements, and despite my...
  41. S

    What is the relationship between the reflection angles in a prism?

    Homework Statement For a beam of light shone on a prism, the reflected beams will give twice the angle of the prism. Homework Equations We know that the angle between the incident ray and the normal = angle between reflected ray and normal The Attempt at a Solution i tried drawing...
  42. D

    Angles Transversed with Centripetal Acceleration

    Homework Statement Okay, so the problem is I need to find the radius of curvature for a proton moving through a uniform magnetic field with initial velocity v for some distance d and exiting at angle θ. I was able to get the correct answer; however, I think the apparent assumption made by the...
  43. T

    Determining angles and the 6 trig functions? D:

    Homework Statement The Attempt at a Solution No attempt, don't even know where to start. I get a point... I can draw a triangle out of it. I can figure out the X and the Y. I know the 6 equations... Sin, Cos, Tan, and the opposites Cosecant, Secant, and Cotangent... I know...
  44. K

    Elastic Collision, Finding Angles Between Particles

    Hi, here's my problem. A particle of m1 and initial speed v0 strikes a stationary particle of mass m2, and scatters at 30 degrees to its original direction with speed v0/3. Find the angle, in degrees, between the directions of the two particles after the collision. I found that the...
  45. H

    What Are the Optimal Kicking Angles for a Field Goal in Football?

    Homework Statement a football kicker can give the ball an initial speed of 25m/s. what are the least and greatest elevation angles at which he can kick the ball to score a field goal from a point 50m in font of the goalposts whose horizontal bar is 3.44 m above the ground. Homework...
  46. K

    Geodesic Dome Angles: Help for Math Wizards!

    Hi, Any math wizards here willing to assist me in determining cut angles for parts to construct geodesic dome greenhouse. I am building a 13' diameter geodesic dome. I am using the info from geodesic dome calculators on line for a 2V version. It is composed of 6 pentagonal frames with...
  47. S

    Gunshot Projectile Motion: Two possible angles*

    Homework Statement The drawing shows an exaggerated view of a rifle that has been ‘sighted in' for a 91.4-meter target. If the muzzle speed of the bullet is v0 = 424 m/s, there are the two possible angles θ1 and θ2 between the rifle barrel and the horizontal such that the bullet will hit the...
  48. E

    Circular Motion at an angle, finding angles and tension

    Homework Statement At the royal show there is a ride for younger children where they sit in a seat and it spins in a circle. The seats weigh 10.0kg and by comparison the mass of the chains holding the seats is negligible. When the system rotates the chains make an angle of 28 degrees to the...
  49. L

    Projectile A - > B , two different angles

    Homework Statement Muzzle velocity at A = Vo. Determine the two angles, theta 1 and theta 2. A is separated from B by a distance L in the x direction and a height H. (B is on a hill above A). Homework Equations The Attempt at a Solution I feel that the important facts of this...
  50. R

    Finding magnitudes of vectors given angles

    Homework Statement Vector A points in the negative direction. Vector B points at an angle of 35.0 above the positive axis. Vector C has a magnitude of 16 and points in a direction 44.0 below the positive axis. Given that A+B+C=0 , find the magnitudes of A and B . Homework Equations...
Back
Top