Angles Definition and 911 Threads

  1. C

    How Do You Calculate Trigonometric Ratios for Angles in Standard Position?

    Homework Statement 1) If the point (-4, 2) lies on the terminal arm of an angle θ in standard position, determine the exact value of csc θ. 2) If sec θ = -5/3 and angle θ terminates in quadrant III, which point must be on the terminal side of θ? 3) If cos θ = 5/13, where θ is in quadrant VI...
  2. M

    Solid angles and position vectors

    I've already posted this question in the math section, but since I got no reply I'll try it here (sorry for the cross-posting). I'm using solid angles to define directions of objects moving from the centre of the sphere towards all points in the space around, which means I divides the (4pi)...
  3. A

    Finding Side Lengths of a Triangle Given Angles & Side a

    A triangle has an angle A=35 degrees and an angle B=40 degress and side a=3680 meters. What are the lengths of sides b&c?
  4. P

    Solving for Tensions with Different Angles

    Homework Statement A climber is suspended between two cliffs and is closer to the left cliff. The left part of the rope makes an angle of 65 to the cliff and the right part an angle of 80 to the cliff. The climber weighs 535N. Homework Equations Trigonometry... The Attempt at...
  5. B

    Centripetal acceleration and angles

    Homework Statement A block is hung by a string from the inside roof of a van. When the van goes straight ahead at a speed of 34 m/s, the block hangs vertically down. But when the van maintains this same speed around an unbanked curve (radius = 120 m), the block swings toward the outside of the...
  6. D

    Calculating Angles for Lowest First 4 Reflections of Diamond

    Homework Statement Diamond crystallises with a cubic unit cell and the lattice is face centred.Calculate the respective angles(in degrees) at which the lowest first four reflections are allowed from a polycrystalline specimen of diamond(given (wavelength)^2/4a^2 = 0.0467,where a = unit cell...
  7. N

    Angles of Nodal Lines (Two point light source)

    A two-point source operates at a frequency of 1.0Hz to produce an interference pattern in a ripple tank. The sources are 2.5cm apart and the wavelength of the waves is 1.2 cm. Calculate the angles at which the nodal lines in the pattern are located far from the sources. (assume the angles...
  8. B

    Optics - diffraction gratings and blaze angles

    Homework Statement Light is incident on the reflecting surface tilted at a blaze angle \gamma with respect to the horizontal non-reflecting screen as shown in the figure (below). The angle of incidence with respect to the screen normal is \theta_i. Consider two points along the reflecting...
  9. W

    Sum of a polygon's interior angles

    For a polygon with n sides, the sum of the interior angles is 180n - 360. If we find n positive numbers that sum up to 180n - 360, does that necessarily mean these numbers can be represented as the inside angles of a polygon with n sides? I can't prove this right or wrong...
  10. Amith2006

    Angles made by angular momentum vector with magnetic field

    Homework Statement 1) For l=3, find the possible angles that the orbital angular momentum vector(L) makes with the z axis? Here the magnetic field acts along the z axis. l is the orbital quantum number. Homework Equations The Attempt at a Solution I solved it in the following...
  11. J

    How Does a Hawk's Collision with a Pigeon Alter Its Flight Path and Speed?

    Homework Statement A 5.4kg hawk flying swoops down at 65 degrees to the horizontal at 18m/s. The hawk grabs a pigeon flying 14 m/s horizontally. The pidgeon weighs 1.2kg. After the collision, what is the speed of the hawk (with the pidgeon) and at what angle to the horizontal is it now...
  12. R

    Forces and Angles Above The Horizontal (2 prob.)

    Homework Statement 1. A sled is pulled at a constant velocity across a horizontal snow surface. If a force of 8.0 x 10^1 N is being applied to the sled rope at an angle of 53 degrees to the ground, what is the force of friction between the sled and the snow? A. 83 N B. 64 N C. 48 N D...
  13. S

    Finding angles quickly in your head

    Here's the free-body diagram of a stupid physics problem I had: http://img211.imageshack.us/img211/5081/triangleey9.png When going over this problem both my book and my lecturer say that \alpha = \theta (they actually don't even mention \alpha; they just write it as \theta to begin with. I...
  14. C

    How can I construct a solution for a constant polygon with 2007 angles?

    I have to find a solution to this problem until next week, so perhaps someone can help: There is a constant polygon with 2007 angles. Put the natural numbers 1,2,.. 4014 on each angle and the center of each side of the polygon, so that the amount of the 3 numbers (angle + center + corner)...
  15. A

    Reference angles always positive?

    Simple question. Are reference angles always positive??
  16. S

    Help with work, angles with friction

    You do 457.2 J of work to move a 4.2 kg chair 9.49 m across the floor at a constant velocity by pushing down on the back of the chair at some angle. If the coefficient of kinetic friction between the chair and the floor is 0.75, what is the angle (relative to the floor) at which you are pushing...
  17. D

    Electrostatics problem (ruddy angles)

    Homework Statement Calculate the magnitude of the field strength at point P as shown. The distance between the centers of the 1.5E-6 C and the 9.2E-6 C charges is 5.6 cm.. Homework Equations E = kq/r^2 E = F/Q E = V/d The Attempt at a Solution Used tan and sin of 50 to find all...
  18. 1

    How can I calculate rotation angles from a 3D vector without a rotation matrix?

    Hello folks! So, I'm working on a java applet where I want to rotate an object to point in the direction that it is moving. I have its velocity stored as a 3D vector (x,y,z) and I am using a 3D library that allows for rotation on any axis (x,y, or z). It's my understanding that I need to...
  19. K

    Need help with vectors, angles, etc please

    I have a problem that I have no way of solving on my own. I would like to know how to move a 3-dimensional object long the surface of a 3-D sphere and have it move in the direction it is facing, relative to the surface. Can someone please help me? I am not very good at math but am trying. What I...
  20. Z

    Calculating Wavefunction Angles in sp3 Hybridization - How to Use Integrals?

    I'm given the following matrix equation: I'm also given: We're supposed to show that the angle between any two of these wave functions is 109.5 (characteristic of sp3 hybridization). I assume I need to calculate the expectation values of x, y and z and then use the dot product, but I'm at...
  21. T

    Acute Angle Between Z-Axis and Surface Normal in Surface and Angles Proof

    Prove that the acute angle \gamma between the z axis and the normal to the surface F(x,y,z)=0 at any point is given by sec \gamma = \frac{\sqrt{F_x^2 +F_y^2+F_z^2}}{|F_z|}} Where i am having trouble is that i do not know what this surface is, can someone help clarify what the surface is. thanks
  22. R

    Why do r and F need to be perpendicular for two angles to give the same torque?

    Unless r and F are perpendicular, there are always two angles between their directions that give the same torque for given magnitudes of r and F. Explain why? Perhaps I cannot visualize the question, but I cannot see how this can be. As the force moves to the perpendicular position the...
  23. C

    Basic angles of refraction and incidence help needed

    Basic angles of refraction and incidence help needed (help still needed) I feel silly for even asking this, but here goes. http://img501.imageshack.us/img501/905/refractionpuzzlerg2.gif The triangle represents a glass prism. The refractive index between air and the prism is 1.55. The...
  24. J

    How Do I Solve These Physics Problems on Forces and Velocities?

    I have a take home quiz for my physics class. Out of the 10 questions I have answered 7 of them, whether they are right I don't know. First and foremost I need help on the ones I haven't solved yet. I am not necessarily looking for someone to give me the answers, but rather help me setup the...
  25. J

    Forces, velocities, and angles

    I have a take home quiz for my physics class. Out of the 10 questions I have answered 7 of them, whether they are right I don't know. First and foremost I need help on the ones I haven't solved yet. I am not necessarily looking for someone to give me the answers, but rather help me setup the...
  26. B

    Speed of a pendulum at certain angles

    A simple pendulum consists of a ball suspended by a string from the ceiling. (Treat the ball as a point particle.) The string, with its top end fixed, has negligible mass, and is non-stretchy. In the absence of air resistance, the system swings back and forth in a vertical plane. If the string...
  27. M

    Two slides have different angles, find the numeric angle

    In a playground, two slides have different angles of incline theta1 and theta2 (theta2 > theta1). A child slides down the first at constant speed; on the second, his acceleration down the slide is a. Assume the coefficient of kinetic friction is the same for both slides. (a) Find a in terms of...
  28. B

    Projectile problem with no angles

    A projectile is fired horizontally from a gun that is 53.0 m above flat ground. The muzzle velocity is 235 m/s. How long does the projectile remain in the air? All of the practice problems in my book are given an angle to work with. For some reason I'm having a hard time starting this...
  29. K

    Vector rotation (possibly Euler angles)

    I'm looking for a method to rotate a 3D vector, and place it at an arbitary 3D point (x,y,z) without changing the vectors magnitude. I have briefly investigated eulers angles (mainly through wikipedia links etc), but don't fully understand the process yet. As an example, given the vector ...
  30. M

    Tension of strings at different angles:

    Hi there- I've been trying to solve this problem for the last hour, and I still feel stuck! So far, I've only seen problems with equal angles between the strings and the horizontal- I have no idea how to solve a problem when there's two different angles! A 45-N lithograph is supported by two...
  31. V

    HELP This has to do with magnitude, resultant, and angles Please answer

    HELP! This has to do with magnitude, resultant, and angles! Please answer! This is due by 10:30 p.m. so please help me by then!:cry: here it is: 3. [Giancoli6 3.P.010.] Three vectors are shown in Fig. 3-32 (A = 68.0 , B = 54.0°). Their magnitudes are given in arbitrary units. Determine...
  32. V

    Proving Angles in a Circle: Angle 2 is Twice Angle 1

    http://s14.photobucket.com/albums/a348/Drakhys-2/?action=view&current=scan.jpg How would I prove that angle 2 is twice the size of angle 1? thankyou, Vash.
  33. A

    Optimizing Sign Visibility: Investigating Angle Variations for Approaching Cars

    "The lower part of a 2.0 meters high road sign is at a distance of 4.0 meters from the car drivers eyes. It's difficult to read the sign at such a distance, as well as when the distance is too short. Investigate how the angle varies when the car is approaching on a straight road. At what...
  34. D

    Why is Refracted Angle > Incident Angle?

    Why is it that the refracted angle > the incident when light moves from a more dense material to a less dense? Is there any way to explain why the angle would be greater? I know the velocity would increase. Wavelenght increases. Frequency remains the same. Correct?
  35. J

    Understanding Oscillator Circuits: Effects of Adding a Second Coil at 90 Degrees

    Hello everyone, In my continuing pursuit of understanding of oscillator circuits, I came up with this question and was wondering if anyone here could give me some insight on this. I drew a picture to help me explain the idea but I would like to know what would happen if you have an inductor...
  36. B

    Can Opposite Angles Determine Special Properties in Quadrilaterals?

    Hi, can someone please help me out? I need to know if I can draw any conclusions from the following. There is a quadrilateral such that two 'opposite' internal angles are 90 degrees. Is there anything that I can say about the line segment joining the two vertices of the quadrilateral which...
  37. Z

    Calculating Impact Energy for Non-90° Angles

    A quick look through the FAQ and search didn't reveal anything so... I know that K.e. = ½MV², however I am looking to find the energy of an impact when φ != 90°. Or to the more specific problem, if I have a Spaceship shaped like a needle moving through space at .9c(Vnet) and a micrometor hits...
  38. R

    What is the measure of each interior angle for a regular triangle?

    The questions asks me to "Find the measure of each interior angle for a regular triangle. Then Round to the nearest tenth if necessary" So, the solution of the measures of the interior angles of a triangle is 180 degrees. There's 3 angles. So each angle = 60. So all i really want to...
  39. R

    Corresponding interior and exterior angles

    SO i have a problem that's "AB ll CD, Find x and y". I got the answer of x=48, =144 Because first the measure they already gave you was 42. As well as y - 12for the other angle measure. And x was the measurement for D. blah it's too hard to explain but i got it correct. My point is that in...
  40. R

    What are the Spherical Interior Angles for Regular and Archimedean Solids?

    Anybody know where to find a listing of the Spherical Interior Angles for Regular and Archimedean Solids. For example on a Buckyball (Archimedean Solid - truncated dodecahedron) should have angles: A: Angle between vertexes (length of Edges in radians) B: Angle from center Hexagon to...
  41. A

    Where Is Earth's Nutation and Does the 23.5° Axial Tilt Ever Change?

    Hi, I would like to see the resemblance between planet Earth and a spherical top. I draw here the x-convention Euler angles as I know them: 24 hours to complete one complete one revolution around it's own z' axes. And the 23.5° Earth axes revolves around the "sun's z axes" - the line...
  42. Z

    How to Calculate the Angle Between Two Celestial Objects?

    Given the right ascension and declination of two objects in the sky. Is there a way to calculate the angle between them? If so, do right ascension and declination need to be converted to radians or can they retain their units?
  43. S

    Friction Question an incline plane with two angles

    Ok I just can't see this questions I don't want an answer I just whant an explation on how to do it. if you can respond today it would be great thanks! an simple drawing like I did would be great thanks! a block weighing 100 Newtons is positioned on a incline that makes an angle of 30 degrees...
  44. N

    Sum of interior angles of cyclic hexagon

    Right I have been given the following problem and cannot resolve it. I have had an attempt but without much success. Could anyone help me with this exercise, please? Hints or a little more welcome :-) A cyclic hexagon is a hexagon whose vertices all lie on the circumference of a circle...
  45. N

    Finding the direction vector with only direction angles

    Hey everybody! Thanks for any help! If I am told a line has direction angles of 60, 45 and 60 and passes through the point (-2, 1, 3). How would I go about figuring out the symmetric equations of the line.. Relatively simple question but I am a tad confused. HELP! THANKS AGAIN!
  46. S

    Proving Identities and Double angles problems

    I've been working at proving these identites and I just can't seem to figure them out, some of them just come to me others I work on them for 10 mintues or more and just get more and more bogged down.:frown: 1) csc2x + cot2x = cotx so far i have 1/sin2x + cos2x/sin2x = cosx/sinx...
  47. M

    Springs, friction, angles, and energy

    i have been given the following problem from everyone's favorite, mastering physics. "The Great Sandini is a circus performer with mass 60.0 kg who is shot from a cannon (actually a spring gun). You don't find many men of his caliber, so you help him design a new gun. This new gun has a very...
  48. M

    Frictional force and largest angles

    A 17 kg block is at rest on an incline with angle 33. The coefficients of static and kinetic friction are 0.7 and0 0.59, respectively. The acceleration of gravity is 9.8m/s^2. 1) What is the frictional force actin on the 17kg mass? 2) What is the larges angle the incline can have so...
  49. A

    Angles on a Sphere: Find 4 Equidistant Points

    When I was looking at a tetrahedral molecular structure, a question arose. In that molecule, there are 4 atoms placed around a sphere, where the bond angle between any two is 109.5o. How could I show that? It's not part of the homework, but I'm just wondering how to find the angle if you have...
  50. C

    How to get mag. & angles of resultant couple moment

    I have another thread for another problem, but no one seems to be responding about this second problem, so i'll post it here. Need to find the magnitude and direction/space angles of the resultant couple moment of two valve handles being turned, as pictured...
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