1. L

    Frame of reference question. Polar co-ordinates

    A lighthouse keeper spots a ship sailing away from the shore. She marks the bearing from North to the ship as \theta=24 degrees and estimates the distance to the ship as 2.4km. The captain of the ship notes the ship is heading \phi = 30 degrees from north. If the captain similarly estimates...
  2. W

    Frenet Frame: Are these two representations the same?

    I have a regular curve, \underline{a}(s), in ℝN (parameterised by its arc length, s). I am trying to define the moving (Frenet) frame of orthonormal vectors \left\{\underline{u}_1(s),\underline{u}_2(s),\dots, \underline{u}_N(s) \right\}. However, looking in different books, I find subtly...
  3. J

    Digital Photo Frame Reviews

    Most digital photo frames are seven to twelve inches in size. The time period between the display of two different photographs is fixed. A digital camera has a flash memory card which has a high power storage and recording ability. It uses this flash memory card to display the images. Some have...
  4. R

    Lengths of Frame Members

    You work in the design department of a company which produces fabricated steel structures and have been given sketches of two frames. For each, work out the lengths of all the members and the angles involved. The roof frame shown below is symmetrical about a centre line axis.
  5. R

    Parallel transport frame

    Hi there, A curve is parameterized by: r(t)={x(t),y(t),z(t)} x, y and z are differentiable infinity times. {T0,N10,N20} is an initial frame at r(0). How to determine the frame through the curve by parallel transporting? I've been surfing the internet, trying to figure out how. Wasn't...
  6. silvercats

    Frame works help

    Basic maths frameworks How to find the reaction force on B in below frameworks? step by step explanation would be appreciated because I can't understand my freak tutorial ! thanks
  7. K

    frames of a hilbert space

    Hi! I came across this problem while I was reading a supplementary material for our course on hilbert spaces. Can anyone help me with this? Thank you! given an orthonormal basis {\phi_{n}} of a hilbert space H and a one-to-one and onto continuous linear transformation T from H to H, prove...
  8. L

    covariant derivative with frame field

    In \mathbb{R}^3 let E_1, \ E_2, \ E_3 be a frame field, with W=\sum f_iE_i, show that \nabla_V W=\sum_j \bigg{(}\nabla_Vf_i+\sum_i f_i\omega_{ij}(V)\bigg{)}E_j So what I have so far is:\nabla_V W=\nabla_V \sum f_iE_i = E_i\nabla_V\sum f_i+\sum f_i\nabla_V E_i now I have that \omega_{ij} is...
  9. M

    Area of frame

    Diagram 5 shows a wire frame.The length of the wire is 60 cm and the radius of the semicircle is r cm (i)show that the area of the frame,L cm^2, is given by L=60r-2r^2-\frac{1}{2}\pi r^2 (ii)Hence,calculate the maximum area of the frame
  10. Focus

    Lie group and the frame bundle

    I am working in a (psuedo) Riemannian manifold with the fibres of orthonormal frame based on some Lie group. From the Levi-Civita connection, I can separate the tangent space of the frame bundle into horizontal and vertical bits, i.e. T(\mathbb{O}M)=H(\mathbb{O}M)\oplus V(\mathbb{O}M). Here...
  11. A

    finite spanning set<->frame

    Show that every finite spanning set for \mathbb{R}^d is a frame for \mathbb{R}^d (frame:\exists A,B >0 \in such that A ||x||^2<=\sum|<x,f_k>|^2<=B||x||^2 ) and that every finite frame {f_1,\ldots,f_n}\subset \mathbb{R}^d, n>d is a spanning set for \mathbb{R}^d
  12. S

    Data Frame Transfer

    I have no idea what this question means. Can someone help me get started? An 802.3 sending node transmits a data frame consisting of 1500 octets. What hex value does the sending node insert in its length field?
  13. Monocerotis

    Completely stumped by a picture frame >_<

    So here is the question: A picture that measures 10cm by 8cm is to be surrounded by a mat before being framed. The width of the mat is to be the same on all sides of the picture. The area of the mat is to equal the area of the picture. What is the width of the mat, to the nearest tenth of a...
  14. J

    Rectangular Prism - Wire Frame

    This question may have one, two, three or four correct answers. A frame in the shape of a rectangular prism is made from 24 cm of wire. Each side length is a whole number of centimetres. Which of the following volumes is possible? A. 4 cm^3 B. 6 cm^3 C. 8 cm^3 D. 12 cm^3 Please guide me...
  15. Z

    Motion in different reference frame

    This is a practice problem for the midterm, any advice and help would be awesome~ thanks everyone~ An airplane moves in a northwesterly direction a 125m/hr relative to the ground. due to the fact that there is a westerly wind (ie from west) of 50 m/hr relative to the ground. Determine how fast...
  16. C

    Truss and frame analysis

    Determine the member forces for all members in each truss shown using the method of joints. Remember to list each member force as either tention or compression.
  17. C

    Ellipse with rectangular frame

    »Write down the equation of an ellipse, that goes through P(1,-2) and whose circumscribed* rectangle's area is minimized.« * (Pretending not knowing that "rectangle" is in fact square.) Set-up: Ellipse through (1,-2): \frac{1}{a^2}+\frac{4}{b^2}=1, rectangle's area: 2a*2b=min. Now, what...
  18. C

    Find the width of a frame

    The printed matter on a 12 by 24 centimeter page of a book must cover 64 square centimeters. If all margins are to be the same width, how wide should the margins be?
  19. S

    Centre Of Mass: Frame

    I don't understand how you would find the centre of mass of CD from AB? Thanks in advance.
  20. J

    Window Frame Optimization Help

    Thought I solved this question, but I did it wrong. Time to start over. "A piece of window faming material is 6m long. A carpenter wants to build a frame for a rural gothic style window where the top is an equilateral triangle. The window must fit inside a space 1m wide and 3m high a) Find...