Angles Definition and 911 Threads

I am trying to prove that the two θ are equal from this picture http://en.wikipedia.org/wiki/File:Double_slit.svg How do I go about proving this?

Homework Statement A passenger on a boat moving at 1.5m/s on a still lake walks up a set of stairs at .5m/s. he stairs are angled at 45 degrees in the direction of motion as shown. What is the velocity of the passenger relative to the water. Homework Equations The Attempt at a...

Homework Statement Find the phase angle between the input and output voltages in the following two circuits - in each case state whether the output leads or lags the input voltage. The second circuit is the same but the capacitor and the resistor are switched around. Homework Equations...

Homework Statement If a force (wind) hits a plane which is at a 45 degree angle, how is that force distributed? How much is translated vertically and how much is translated horizontally? My guess is that 50% is translated vertically and 50% is translated horizontally. Here is an image to...

Hello. Firstly, I hope this is the right sub-forum for this question. Here's a quick question that I have. After an electron-positron pair production, do the angles that the paths of the electron and the positron make with the original path of the photon have to be equal? Another way to ask...

Consider a vector in 3D. Its projections on two planes, say YX and YZ planes, makes some angle with the vertical axis ( the y-axis in this case). I know these two angles (I call them projected angles). This is the only information I have about the vector. I need Euler angles which when...

In attempting this question, I decided to expand the first statement. Can anyone help me out? Many thanks. Homework Statement If \sin A=\sin(A+30^{\circ}), show that \tan A=2+\sqrt{3}. Homework Equations The Attempt at a Solution \sin A=\sin A\cos30+\cos A\sin30 \sin A=\frac{\sin...

Hey guys, I am having a little trouble determining the final answer to this question. Basically an object is being pulled by two forces and I am suppose to find the Net Force F1 = 12 N at an angle of 32 degrees (upwards) F2 = 15 N at an angle of 24 degrees (downwards) So what I did was...

Homework Statement I conducted an experiment which involves measuring two distances (Y and L) and have used tan to determine the angle, then finally calculated the sine of the angles for use in my analysis. I have uncertainties in both length measurements and am unsure how to propagate the...

This is my first year taking a Physics class, so this might just be a simple question but I'm stuck. Homework Statement A stunt driver wants to make his car jump over eight cars parked side by side below a horizontal ramp. (a) With what minimum speed must he drive off the horizontal...

A bag of cement of weight 325N hangs from 3 wires as shown in figure (I've attached it). Two of the wires make angle1=60oand angle2=25o with the horizontal. If the system is in equilibrium, determine the tensions of T1, T2, and T3 If you can't see the image, the T1 and T2 are suspended from a...

Trying to build a desk. Have all the standard measurements but having issues figuring out what the angles I need for the support beams I have attached a drawing the blue circles are the angles that I need to figure out. Also I need to know how long my beam has to be before being cut(green line)...

Hi everybody; I am a bit stuck with negative angles. What I know is that: If we measure an angle from x-axis clockwise direction, the angle is negative. However, I am a bit dissapointed because while I researched the web I see the negative agles only in topics subject to trigonometry. So I...

Homework Statement My knowns are: the trapezoid has a perimeter equal to 180 inches and it's base angles are ∏/3 The unknowns are: the lengths of the base (x) and the length of one of the slanted sides (y) as well as the relationship between x and y Homework Equations Trig equations...

is there a relation between the numerical answers of cos5A and cosA? sin4A and sinA? i want to work backwards, if it is possible. tried deriving a formula by myself, but couldnt.:(

Edit: Nevermind, it has been resolved. Homework Statement I have been attempting to solve what seems like a relatively pedestrian statics questions, but for some reason my answer is being marked as incorrect. The problem is as follows: Determine the magnitude and coordinate direction...

imagine we rotate a vector centered at the origin with euler angles alpha,beta,gamma. now the question is, can we do this rotation by the means of defining a vector N(which its length is 1).and rotating the vector zeta radians counter clockwise around N? I think it must be possible and I want...

1. How does the moon's diameter compare with the distance between Earth and the Moon Tape a small coin, such as a dime to a window and view it with one eye so that it just blocks out the full Moon. This occurs when your eye is about 110 coin diameters away. Then the ratio of coin diameter/...

Homework Statement A block with mass M is held statically on an overhang by a force Mg applied horizontally and the force of friction on the overhang. What are the normal and frictional forces? For what angles θ does the block remain at rest? The Attempt at a Solution In the picture...

Homework Statement A vector is given by R = 2.00 i + 1.70 j + 2.81 k. (a) Find the magnitudes of the x, y, and z components. x = 2 y = 1.70 z = 2.81 (b) Find the magnitude of R. 3.85 (c) Find the angle between R and the x axis. ...

Why are reference angles necessary in trigonometry. I understand they are the acute version of an obtuse angle.

Finding the total distance a jaguar has jumped from a 30° angle at 3.33m/s. I've split the jump into horiz./vert. components: Vertical: v sin(θ) = 3.33sin(30) = 1.67 ms-1 Horizontal: v cos(θ) = 3.33cos(30) = 2.88 ms-1 I am just unsure as to how to find the time taken to reach maximum height...

Conjecture Regarding Rotation of a Set by a Sequence of Angles. Consider the following sequence, where the elements are rational numbers mulriplied by \pi: (\alpha_{i}) = \hspace{2 mm}\pi/4,\hspace{2 mm} 3\pi/8,\hspace{2 mm} \pi/4,\hspace{2 mm} 3\pi/16,\hspace{2 mm} \pi/4,\hspace{2 mm}...

Homework Statement I have an assignment that is to prove for instance the range of a projectile that is fired from 40 degrees will be the same as one fired from 50 degrees cause they are complementary but I need a general way to prove it for all angles less than 90 degrees.Homework Equations...

Thought I was done but not the case... Homework Statement Alright so as stated a couple days ago... "projectile is shot from the edge of a cliff 125 m above the ground @ an initial speed of 65 m/s at an angle of 37° with the horizontal from the cliff." ---- As helped earlier I have...

Homework Statement A particle decays to two photons. In the rest frame the two photons are emitted on the x-y plane, in opposite directions along a line that forms an angle alpha with the the x axis. Derive the momentum four vector of the two photons in the lab frame. Homework Equations...

For part (i), my answer is correct but my answer for (ii) seems to be a little bit out. I can't spot where I've gone wrong. Can anyone help me out? Many thanks. Homework Statement Q. In the given triangle, find (i) |\angle abc|, (ii) |\angle bac|. The Attempt at a Solution (i) cos B =...

Homework Statement A 3000-kg Cessna airplane flying north at v1 = 70 m/s at an altitude of 1750 m over the jungles of Brazil collided with a 7000-kg cargo plane flying at an angle of θ = 34° north of west with speed v2 = 111 m/s. As measured from a point on the ground directly below the...

thanks.. an explanation on how to do it will help!1.Can a triangle have angles equal to a. 55°, 65°, 70° b. 53°, 64°, 73° c. 80°, 105°, 5° 2. In (triangle)△DEF, <D, <E and <F -44° (deg), Find <D and <E

angles -- why in radians instead of in degrees? greetings, why all the angle in electrical is represented in radian instead in degree? advanced thanks

Homework Statement Explain step by step how angle a is equal to angle a Homework Equations The sum of the angles in a triangle equal 180 degrees. at a solution[/b] http://s16.postimage.org/k0rslli05/untitled1.png Made two right triangles but I am not sure how to connect angle...

While I think that the phenomena of Quantum Entanglement exists, it's real; it's interesting to understand more about it. How does QE/QM explain more mismatches (relatively to simple probability calculations) in Bell's test at wider angles? Or alternatively: Why does/would QE result in lower...

Hi everybody, I have a couple of equations and I need to find the values of three variables (δ, λ, and θ). The equations are: M[11] = -(sin(δ)*cos(λ)*sin(2*θ)+sin(2*δ)*sin(λ)*sin(θ)^2)*M[0]; M[12] = (sin(δ)*cos(λ)*cos(2θ)+(1/2)*sin(2*δ)*sin(λ)*sin(2θ))*M[0]; M[13] =...

Homework Statement The chair o plan seats are supported by chains hung from a circular structure. What angle to the vertical will be formed by the chain of a chair-o-plane seat is occupied by a 45 kg child if the tension is 550 N... I was able to solve this one.. THe question I need a help in...

Homework Statement City Latitude(degrees) Longitude(degrees) LOS ANGELES 35.20 N 118.03 W CHICAGO 41.82 N 87.62 W CORVALLIS 44.53 N 123.30 W MONTREAL 45.50 N 73.58 W...

In robotics, you have a co-ordinate frame which is at the base & another which is at the next joint. You want to describe the position and orientation of the 2nd frame with respect to the first in terms of position and orientation. For the position, you use a translation matrix. The...

Normally with column vectors, we premultiply rotation matrices if the angles are with respect to fixed axis. Why then do we post multiply if the angles are Euler Angles, angles with respect to the mobile axis?

Here's a picture of an irregular tetrahedron, for reference: The base triangle (ABC) is completely known (lengths AB, AC, BC, and the angles between them are all known). The 3 angles at vertex P are also known (APB, APC, and BPC). I believe that is enough information to completely solve the...

Styrene Maleic Anhydride is a tricky polymer that I've been researching over the last few days. There is very little information online, and I've been trying to figure out the bond lengths and angles. I know the bond angles inside the benzene are 120 degrees, and the Carbon attached to the...

Homework Statement Find and compare the transformations of the angle of the velocity vector of a particle and the angle of an inclined stick. The relationship between the two frames is as usual. In frame S' a stick makes an angle of θ' with the x' axis. What is the angle θ measured in the S...

Apparently you can calculate the angle between two vectors even when they occupy say 7 dimensions. I have trouble believing that. To me if a vector occupies 7 dimensions than it is incommensurable with another vector occupying 7 dimensions.

Hi, I'm trying to find a general expression for the scalar triple product for 3 vectors in a simultaneous configuration, that depends only on the inter-vector angles, A1, A2 and A3. I have expressed this quantity in terms of the spherical polar coordinates of the vectors (the length being...

Snell's Law of Angles says that : sinA/sinB = nB/nA but in order to find critical angles B has to be 90° . I understand that in order to have total internal reflection that nB/nA < 1 but why can't there be a CRITICAL angle when nB/nA > 1 ? sinA would have to be greater than 1 which...

I know this is rather trivial question but it's not homework! I need this as part of a bigger project. What I have to do is rotate my reference frame to another one. I want my new z-axis to be a vector Z=(Z1,Z2,Z3) Following the notation of this wikipage...

Homework Statement A child of weight w sits on a swing of length l. A variable horizontal force P that starts at zero and gradually increases is used to pull the child very slowly (so the kinetic energy is negligible small) until the swing makes an angle θ with the vertical. Calculate the work...

Homework Statement Find the phase angle between i1 = -4 sin (377t + 25) and i2 = 5 cos (377t - 40) The Attempt at a Solution I first made i2 in terms of sine: 5 cos (377t - 40) => -5 sin (377t + 50) => 5 sin (377t + 230) Now to make i1 positive as well: -4 sin (377t + 25) => 4 sin...

How do you prove that angular velocity is just the time derivative of each Euler angle times the basis vector of its respective frame? I remember it used to be perfectly clear to me a while back, but now I don't remember how the result was derived, and I couldn't find it in any of my books I...

Homework Statement I am trying to find the face angles on a tetrahedron. I have only the base edge lengths, the angles connected the base edges and an (approximate) height of the top/non-base vertex. I might be able to extrapolate other information from images of the base of the tetrahedron...

Homework Statement A rod lies at an angle α with the x'-axis of an inertial frame moving at a speed v along the x-axis(x and x' are parallel) of another inertial frame. The rod makes angle β with the x-axis of this frame. Find the relation between α and β. Variables: α,β,v and define...

Homework Statement A sailboat is manufactured so that the mast leans at an angle α with respect to the deck. An observer standing on a dock sees the boat go by at a speed v. What angle (β) does the observer say the mast makes with the deck of the boat? Homework Equations The...