Angles Definition and 892 Threads

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...

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...

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

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...

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...

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...

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...

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...

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...

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...

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

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.

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...

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

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...

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 +...

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...

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...

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...

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...

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?

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...

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

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

I am trying to do some calculations that involve cubic Bezier curves. I've been looking all over the place for information about Bezier curves, but I can't find anything that has what I'm looking for. I need to be able to figure out the length of any curve with known control points...

Can someone help me with this problem? I am stuck. So far I have:net Force (x) = T1cos30 - T2cos(θ) = 0 net Force (y) = T1sin30 + T2sin(θ) - 120N - 400N = 0 From equation 1 ---> cosθ = (T1cos30)/T2I attached a picture of the problem. Not...

Hi! I have a question about approximation of functions with small angles. I was looking through some notes from my teacher and didnt understand why the following approximation is valid. We have a system which is at equlibrium at an angle, say a. Now we wanted to se what happens with the...

Homework Statement A rope forms a Y. At the end of the Y hangs a block with a W= 100N Whole the two upper ends are on the walls. (Left side) T{1} with an angle of 90 degrees (Right side) T{2} with an angle of 58 degrees Find the tension of each rope on the wall. Homework Equations No definite...

Homework Statement This question is on my physics homework, I guess it could be posted elsewhere, but I'm not sure where. Here is the problem: Which of the following are the same as 18 degrees below the -x-axis? Choose all that apply: !The choices I selected are in red! A) 72 degrees left...

Homework Statement See attached photo. Find the resultant displacement measured from the starting point. Homework Equations The Attempt at a Solution When it comes to angles, i sometimes get confused when to add 180 or not. FOr the first two distances, we don't have to find...

Not quite sure how central angles ended up in a PreCalc class, but oh well. Okay so, I'm given this picture And this information: A satellite is in orbit 2000 kilometers above the Earth. It is scheduled to pass directly over a tracking station at noon. The satellite takes 2 hours to make...

Hi.. The wikipedia article on euler angles claims that the Euler angles in zxz convention are unique if we constrain the range they are allowed to take (except in the case of the gimbal lock). This seems reasonable. But can someone give me a reference... a book or a paper where this is...

I have multiple robot cells that i would like to move fixtures from robot to robot with the out come of the part to be perfect. in order to do that i need to make sure my work object is in the same spot each time. so i need to find the yaw pitch and roll and convert them into Euler angles. On...

URGENT HELP needed on Displacement Angles Due tomorrow Edit: with the help of second poster, I was able to solve it out. Btw I got 15 meters west and 11.34 meters south for the second one

"obvious" question on angles and solid-angles Hello, I have found in http://www.cg.tuwien.ac.at/hostings/cescg/CESCG97/csebfalvi/node2.html" an important statement about solid angles. Namely, the differential solid angle d\omega is related to an oriented differential surface area dA placed at...

What is the easiest way to see that, in a regular polyhedron, the sum of the face angles about each vertex is less than 2π? This seems elementary, but I truly have very little background in geometry. Preliminary searches on PF and Google/Wikipedia didn't turn up anything substantial aside from...

Homework Statement At one instant ,ships X and y are at a distance of d from each other.THe velocities of ship x and ship y are u and v respectively. Angle a and b are acute. Find the tangent of angle betweeen the direction of relative velocity and \vec{XY} Homework Equations The...