Cone Definition and 514 Threads

  1. S

    Spherical limits of integration for a region bounded by a cone and a praboloid

    Hi everybody, I am trying to solve the following problem and I get stuck on the last question. I would appreciate a lot that someone helps me . Here is the problem: Let D be the region bounded from below by the cone z= the root of (x^2 + z^2), and from above by the paraboloid z = 2 – x^2 –...
  2. R

    Is a Circle Always Formed When Cutting a Cone at Any Angle?

    I was taught that if you cut through a cone at any angle you will end up with a circle shape at the cones edge. Is this true?
  3. O

    Lagrangian of a particle moving in a cone

    Homework Statement Homework Equations Euler-Lagrange equations of motion The Attempt at a Solution Part a): Particle must move on surface (one constraint). Number of generalised coordinates = 3N - K where N = number of particles and K = constraints. Therefore 2 generalised coordinates are...
  4. C

    MHB Maximum Volume of a Right Circular Cone with Given Slant Height?

    > > > What is the maximum volume of a right circular cone with a slant height of \sqrt{3} \ units?Feel free to use Volume \ = \ \dfrac{1}{3}\pi r^2h.
  5. PhysicoRaj

    Gravitational waves in elsewhere of light cone

    Hello every one, This might sound as much stupid as it is confusing for me. Suppose the sun vanished right now (that would not happen practically, but I'm not concerned with that), then it will not be less than approximately a little more than eight minutes for us to know that the sun has gone...
  6. H

    How does circular motion in a cone without gravity work?

    How does circular motion in a cone without gravity work? If I have an object and I let it circle through the inside of a cone (with gravity) the two forces that act on the object are gravity and the support force. The resultant of the two forces lies on the plane of the circular motion and is...
  7. T

    Force on a point charge at the tip of a solid uniformly charged insulating cone

    Homework Statement A solid insulating cone has a uniform charge density of rho and a total charge of Q. The base of teh cone had a radius of R and a height of h. We wish to find the electric force on a point charge of q' at point A, located at the tip of the cone. (Hint: You may use the...
  8. I

    Prove all vectors lie on a cone (Laue Cone)

    Homework Statement Consider a family of planes that belong to a zone axis. In the Laue experiment, the incident beam has a direction s0, which is fixed. Each plane in the zone diffracts a particular X-ray wavelength into a direction s,which is different for each plane. You are told that all...
  9. K

    Maxwell's Demon: would a cone work?

    Maxwell's demon is the little guy who opens an atomic door to a container to let atoms fly in, but shuts it before an atom flies out, thus increasing the internal pressure. Suppose the walls of a container had several small cone-shaped holes built into it. The inside hole might be pretty...
  10. T

    Z Center of mass of an ice cream cone

    Homework Statement The z com of the entire ice cream cone, the base being an inverted right circular cone, the top a hemisphere. Equal density throughout. Must solve using integrals and density relationship. Homework Equations The z com of the top hemisphere (ice cream) is equal to 3/8 R...
  11. S

    Finding the volume of the cone using cylindrical polar coordinates?

    The cone centre is the z-axis and has base ρ=1 and height z=1, I'm looking at the lecture notes and it says the limit φ=0 to 2pi, z=0 to 1, ρ=0 to (1-z). Could someone tell me where the (1-z) comes from please? Why is it not 0 to 1?
  12. BWV

    Quantum tunnelling outside the light cone?

    Zee's QFT in a Nutshell makes a short comment in the first chapter about the possibility of particles tunnelling outside their light cone - is there some probability that a particle could do this? I know the neutrino thing has been debunked as a faulty cable, but did not see this offered as an...
  13. L

    Moment of inertia tensor of hollow cone

    Homework Statement Find the inertia tensor for a uniform, thin hollow cone, such as an ice cream cone, of mass M, height h, and base radius R, spinning about its pointed end. Homework Equations I_{zz} = \sum x^{2}+y^{2} \rho = \sqrt{x^{2}+y^{2}} The Attempt at a Solution I first...
  14. C

    De Sitter Light Cone: Exploring Space-Time Diagrams

    Hey there! I'm relatively new to this website and I have a quick question. If I have some function t(x), that is time for a given x, with a M (mass) constraint, namely... M^2 = 1 --> Null M^2 > 0 --> Time-like M^2 < 0 --> Space-like If I wanted to see what these space-time...
  15. F

    Calculating Electric Flux Through a Cone

    Homework Statement A cone is resting on a tabletop as shown in the figure with its face horizontal. A uniform electric field of magnitude 4550 N/C points vertically upward. How much electric flux passes through the sloping side surface area of the cone? Homework Equations flux = ∫...
  16. M

    Calculating Spiral Length in a Cone: Can You Help?

    Hi everyone, I need some help ASAP please! I have forgotten how to calculate the length of a spiral in a cone. I am really only interested in part of the cone from where the diameter is 8m to the base where it will be 10m in diameter. in this part of the cone there will be 5 rotations each...
  17. fluidistic

    Rigid body (mass sliding over a cone)

    Homework Statement There's a problem that I don't even know really where to start. It seems extremely complex to me. Basically there's a reverted cone of mass M with a mass of mass m that can slides over it without friction. But there's a constraint of motion for the particule, it must stay...
  18. J

    Surface charge density on conducting cone with point charge inside

    Homework Statement Calculate the surface charge density on a thin insulated and uncharged cone, which has a point charge inside of it on the cone axis. Furthermore, calculate the force between the point charge and the cone. Homework Equations The relevant equation is the Poisson equation...
  19. Z

    Is the Light Cone a Valid Representation of Light's Behavior?

    As smatter in the subject therefore I have the following confused questions about the light-cone. As we all know that when a flash of light is released from source, light-rays spread out isotropically in space, tracing out a cone on a space-time diagram. As "light-cone" is expanded at the...
  20. B

    Calculating Cone Surface Area | Step-by-Step Guide

    Homework Statement I understand everything except for the part where the -1 pops out of nowhere on step 4. why? how?
  21. N

    Finding surface area of cone in spherical coordinates

    Hello everyone, I recently tried to find the surface area of a hollow cone (there is no base, like an ice cream cone) using spherical coordinates. With cylindrical coordinates I was able to do this easily using the following integral: \int \int \frac{R}{h}z \sqrt{\frac{R^{2}}{h^{2}} + 1}...
  22. Y

    Deducing the volume of an elliptical cone

    Here again Homework Statement Find the volume of a right elliptical cone with an elliptic base with semi-axes a and b and heigh h Homework Equations So: \frac{x^2}{a^2}+\frac{y^2}{b^2}=1 The Attempt at a Solution That's what I have, but answer should be...
  23. E

    Integral between a cone and a cylinder

    Find the mass of the solid bounded by the cylinder (x-1)2 + y2=1 and the cone z=(x2+y2) 1/2 if the density is (x2+y2) 1/2 I know that I have to substitute for cylindrical co-ordinates x=rcos(theta), y=rsin(theta), and z=z, and then use the change of variables formula to get the mass by...
  24. S

    Volume of Frustum of a Right Circular Cone

    Homework Statement A frustum of a right circular cone with height h, lower base radius R, and top radius r. Find it's volume. Homework Equations We are currently learning the Method of Washers and the Method of Cylindrical Shells so I believe we are supposed to use this somehow. The...
  25. G

    How to Optimize Cone Volume with Given Slant Height?

    Hello there :) I'm having tons of trouble figuring out how to finish this problem. A cone is to be constructed having a given slant height of l>0 . Find the radius and height which give maximal volume. I am unsure of which variables to keep in order for it to be maximized, and how to...
  26. R

    How to make an experiment to find the value of the Drag Coefficient of a Cone?

    How can I design an experiment to find the drag coefficient of a cone without knowing the force of drag that is acting on the cone? Is this even possible?
  27. S

    If Geodesic are light cone, how can be test particle trajectiories

    I had this doubt studing GR, but let's consider SR for semplicity, where g_{\mu\nu}=\eta_{\mu\nu}the geodesics are 0=ds^2=dt^2-dr^2 we obtain the constraint we obtain the constraint r=(+/-)t So it is a well known light cone, but in SR we have that a (test?)particle can always move in a...
  28. J

    Hopefully last question on circular motion (on a cone)

    a smooth hollow circular cone of semi-angle y is fixed with its axis vertical and its vertex A downwards. A particle P,of mass m,moving with constant speed V describes a horizontal circle on the inner surface of the cone in a plane which is at a distance b above A. show V^2=gb...done b)...
  29. B

    Intersection of a sphere and a cone. (projection onto the xy-plane)

    Part of a chapter review problem. Say you have a sphere centered at the origin and of radius 'a'. And you have a (ice-cream) cone which has it's point at the origin and phi equal to ∏/3. How do I find the equation of their intersection? Which is the projection onto the xy plane...
  30. B

    Solving Geodesics on a Cone Using Euler-Lagrange

    Homework Statement We shall find the equation for the shortest path between two points on a cone, using the Euler-Lagrange equation. Homework Equations The Attempt at a Solution x = r sin(β) cos(θ) y = r sin(β) sin(θ) z = r cos(β) dx = dr sin(β) cos(θ) - r sin(β) sin(θ) dθ...
  31. X

    What is the surface integral of a cone in polar coordinates?

    Homework Statement g(x,y,z) = z2; Ʃ is the part of the cone z = \sqrt{x2+y2} between the planes z = 1 and z = 3. Homework Equations Conversion to polar coordinates ∫∫Ʃg(x,y,z)dS = ∫∫Rg(x,y,f(x,y)) \sqrt{fx2 + fy2+1} The Attempt at a Solution If we're talking in terms of r and θ...
  32. T

    Finding Area Between Cone and Sphere

    Homework Statement Find the volume bounded between the sphere of radius a centered at (0,0,0) and the cone z=sqrt(x2 +y2). The Attempt at a Solution So, subbing our definition for z into the the equation for a sphere of radius a centered at (0,0,0): 2x2 + 2y2 = a2. Converting to...
  33. L

    Mass on the inner surface of a cone langrangian

    Hi everyone Homework Statement I have a cone, upside down and a mass m in it, also a homogenous gravitiy field. I found the Euler-Lagrange equation already, which led to 2 equations of motion. Now I want to find a stationary path ( acceleration=0)Homework Equations - The Attempt at a Solution...
  34. T

    Is it Reasonable to Assume a Circular S in Proving Properties of a Cone?

    Homework Statement A solid cone is obtained by connecting every point of a plane region S with a vertex not in the plane of S. Let A denote the area of S, and let h denote the altitude of the cone. Prove that: (a) The cross-sectional area cut by a plane parallel to the base and at a distance t...
  35. J

    Point charge inside thin insulated cone

    Homework Statement My problem is the following:There is a point charge inside a thin uncharged and insulated metal cone. Calculate the charge distribution on the cone and the force between the point charge and the cone. I presume "thin cone" means only the infinitely narrow surface of a...
  36. X

    Yet another Lagrangian problem. Motion in a cone

    Man I hate to make two post in one day but I am really stuck! Homework Statement A particle slides on the inside surface if a frictionless cone. The cone is fixed with its tip on the ground and its axis vertical. The half angle of the tip is α. Let r be the distance from the particle to the...
  37. B

    Derivative of a right circular cone

    inverted right-circular cone, with radius at the top 15 meters and depth 12 meters. rate of 2 cublic meters per minute. How fast is the depth increasing at the instant when the depth is 8 meters. When i try to solve it I get an equation with 2 varibles.
  38. J

    Point charge inside insulated thin cone

    My problem is the following:There is a point charge inside a thin uncharged and insulated metal cone. Calculate the charge distribution on the cone and the force between the point charge and the cone. I presume "thin cone" means only the infinitely narrow surface of a cone.The relevant equation...
  39. P

    Elementary Differential Geometry: Cone Not a Surface - Exercise Problem

    cone as surface... In Barrett O'Neill's Elementary Differential Geometry book...he says that the cone M:x^{2} + y^{2}=z^{2} is not a surface in that there exists a point p in M such that there exists no proper patch in M which can cover a neighbourhood of p in M Intuitively I realize that...
  40. F

    Rate related problem with irregular cone and and time delay

    A water glass (10 cm diameter at the top, 6 cm diameter at the bottom, 20 cm in height) is being filled at a rate of 50 cm^3/min. Find the rate of change of the height of the water after 5 seconds. V=1/3(3.14) r^2h I'm a little unsure how to approach this problem for two reasons. A) The glass...
  41. X

    Center of mass of cone using cylindrical coordinates

    Homework Statement Set up intergral expression for center of mass of a cone using cylindrical coordinates with a given height H and radius R Homework Equations rdrddθdz is part of the inter grand. M/V=D volume of cone is 1/3π(r^2)H The Attempt at a Solution dm=Kdv dv=drdθdx K...
  42. S

    How do I find the center of mass of a cone?

    Im trying to figure out the center of mass of a cone for this research I'm doing. How do I find the center of mass of a cone?
  43. Simon Bridge

    Volume between truncated cone and an inclined plane

    This is something I remember as a standard problem given to college math and physics students ... I've been hunting for a model answer online but no luck: everyone is happy to do the cylinder on it's side or a truncated cone or the intersection of two objects with a lot of symmetry in common but...
  44. J

    How Do You Calculate the Moment of Inertia for a Cone?

    Homework Statement Find the moment of inertia of a right circular cone of radius r and height h and mass m Homework Equations I = ∫r2 dm V = 1/3*π*r2*h The Attempt at a Solution Assume density is p dm = p dv divide both sides by dr dm/dr = p dv/dr dm/dr = p (d/dr * 1/3*π...
  45. G

    How Do You Calculate the Center of Mass for a Cone?

    Homework Statement Calculate the X_com of the cone of mass M in terms of quantities given in the picture. The density of the cone is uniform. See the attachments for the picture. Homework Equations The Attempt at a Solution When I did it I got X_com = (3L)/2 and I am...
  46. G

    How Do You Set the Integration Limits for x and y in a Cone's Volume Integral?

    I have the cone x^2 + y^2 <= z^2 with |z| <= 2 The vector function F = (4x, 3z, 5y) With the divergence theorem I managed to reduce the equation to ∫∫∫ 4 dxdydz Now the problem is finding out the limits. I know z goes from 0 to 2, but what about x and y?
  47. G

    Minimum Radius Cylinder for Tangent Line-Contact with Cone

    If I have a 45° right-angle cone and I place it on a table on the conical surface (not the base), there should be a line-contact along the cone (the table is tangent to the conical surface). The table can be seen as a cylinder with an infinite radius, so, my question is, what is the minimum...
  48. M

    Finding Surface Area Cone through integration

    Homework Statement Find the surface area of the cone with the following equations: x= u sin(a)cos(v) , y= u sin(a)sin(v), z=u cos(a) where 0<=u <=b , 0<=v<=2(pi), a is constant! The Attempt at a Solution Trying to solve this I first calculate the absolute value of the cross product of r'(u)...
  49. Twinflower

    Determine resistance in a cone formed carbon resistor

    Homework Statement I have to determine the resistance of a cone shaped resistor with the following dimmensions: Height at the first end: 1mm Lengdt: 250mm Height at the last end: 0.5 mm Rho: 14.5^10-6 Ohm*m Homework Equations \Omega = \frac{\rho \times L}{A} The Attempt at a...
  50. Z

    Volume of Cone with Inscribed Sphere

    Homework Statement A cone is circumscribed around a sphere. The radius of the sphere is 5 units. Write the volume of the cone in terms of x. There is a diagram.. I will try to describe it: It is a cross section of the object (sphere in cone). From the center of the circle to the bottom left...
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