Pendulum Definition and 1000 Threads

  1. P

    Question about a Conical Pendulum

    Homework Statement A conical Pendulum, a uniform, thin rod of mass m and length l, rotates about a vertical axis with angular velocity omega. Find the angle between the vertical and the rod. Homework EquationsThe Attempt at a Solution I know the usual approach to solve this question, write the...
  2. Priyadarshini

    What is the Angle Made by a Pendulum Using Parallel Lines?

    Homework Statement Homework EquationsThe Attempt at a Solution Using parallel lines I got the angle as theta.
  3. Aerodfocker

    What does mg(theta) means in the equation of motion?

    In the case of inverted pendulum attached in a cart with external force U on it, the equation of motion is like U - mg(theta1) - mg(theta2) = m*dv/dt I don't really understand the mg*theta part what does it mean ...should not be sine or cosine fn there with theta ? can anyone give me some...
  4. Cathr

    How Does Energy Conservation Apply in a Pendulum-Object Collision?

    1. A ball hanging on a pendulum hits an object standing on the table. The interaction is elastic and linear. After that, the object falls on the floor. Homework Equations From state 1 to 2, we have the conservation of the potential energy of the pendulum to its kinetic energy, right before...
  5. G

    Pendulum: Energy is conserved but not momentum

    Hi. In an ideal pendulum, energy is conserved. Potential energy gets transformed to kinetic energy and vice versa. However, momentum is not conserved. The latter means that the pendulum is not an isolated system, which is plausible, since gravity is an external force. But why is energy...
  6. Nicholaz99

    Tension in string for a bob pendulum

    Homework Statement ------------------------------------- |.\ |...\ |...\ |...\ Q...O P O=the bob Teta=60 degree The bob of a simple pendulum is released from rest at P. The mass of the bob is m and...
  7. D

    Find the period of a small oscillation

    Homework Statement A rod of length ##2L## is bent at point of its middle so that the rods now created are in a upside V shape and the angle between them is ##120°##. The system oscilates. Find the expression of the period of oscilation. Homework Equations 3. The Attempt at a Solution [/B] I...
  8. X

    Maximum Kinetic Energy from a Physical Pendulum

    Homework Statement Determine the maximum kinetic energy of a uniform rod of mass 0.5Kg and length 0.75 that has an angular displacement of 5 degrees. Homework Equations y = rsin (x) where x is the angular displacement The Attempt at a Solution Using conservation of energy ETotal = EMech +...
  9. Hijaz Aslam

    Change of Time period of a pendulum with additional mass

    Homework Statement Q. [/B]The bob of a simple pendulum has a mass ##m## and it is executing simple harmonic motion of amplitude ##A## and period ##T##. It collides with a body of mass ##m_o## placed at the equilibrium position which sticks to the bob. The time period of the oscillation of the...
  10. P

    Pendulum with a spring attached

    Homework Statement Mass = 0.2 kg Length of pendulum = 0.2 m Force constant 3 n/m Homework Equations T = 2pi rad(m/k) Sum of Torque The Attempt at a Solution I am really confused on where to start. I know you simply cannot plug it into the first equation listed above since all the mass isn't...
  11. A

    Pendulum Question Homework: Resolving Tension Components

    Homework Statement A pendulum is hanging from the ceiling of a cage. If the cage moves up with constant acceleration a, its tension is T1. If it moves down with the same acceleration a then the tension is T2. If the cage moves horizontally with the same acceleration a, then the tension is T...
  12. A

    Simple pendulum in different situations

    Say there is a pendulum which is suspended by a massless thread or rod or whatever, the bob is spherical and hollow. Now consider 2 cases 1) the pendulum is completely filled with water 2) the water inside freezes. will there be a difference in the time periods? If so, why?
  13. N

    Different methods of finding the weight-work in a pendulum

    Homework Statement In a physical, or a simple pendulum, to get the velocity of the pendulum at some point, we apply the kinetic energy theory, and use m*g*h to calculate the work done by weight, I'm wondering if there are any other ways to calculate the work? I don't care how complicated it...
  14. gracy

    Simple pendulum with Charged bobs

    If two simple pendulum with charged bobs hanging from the same point are taken in a satellite ,then their strings will become perfectly horizontal. I think that should be the case when these bobs are charged with similar charges and hence repulsion occurs but what if the bobs are oppositely...
  15. F

    Period of Vibration of Torsion Pendulum

    Homework Statement Given the period (T) and the moment of inertia (I), find the Torsion constant (K) T= 1.32s I= 0.0383 kgm^2 Homework Equations The Attempt at a Solution The answer is K=0.8678, I'm not really sure how to get the answer, but I think it has to do with the units.
  16. A

    Determining the Spring Constant for a Pendulum with a Spring-Loaded Launcher

    Homework Statement A pendulum, initially at equilibrium, is set into motion by a spring-loaded launcher (compressed a distance of 0.0150 m) which fires horizontally. If the mass of the pendulum bob is 0.340 kg and it rises to a maximum height 0.120 m (relative to equilibrium), what is the...
  17. ellipsis

    Behavior of triple pendulum with heavy end mass

    Is a triple pendulum with a significantly heavy end-mass supposed to spaz around? Using the Euler-Lagrange formula in Mathematica, I've found (and simulated http://poteat.github.io/triplependulum.html) a triple pendulum system with arbitrary masses and lengths. The rods are massless (so no...
  18. C

    Maximum Angle of a Simple Pendulum with Given Parameters

    Homework Statement A simple pendulum of length 2.00 m is made with a mass of 2.00 kg. The mass has a speed of 3.00 m/s when the pendulum is 30.0° above its lowest position. (a) What is the maximum angle away from the lowest position the pendulum will reach? Homework Equations...
  19. Safinaz

    How Does a Circular Hoop's Oscillation Period Change When Displaced by a Breeze?

    Homework Statement the period of a physical pendulum is ## 2\pi \sqrt{I/mgh}, ## where I is the moment of inertia about the pivot point and d is the distance from the pivot to the centre of mass. A circular hoop hangs from nail on a barn wall. The mass of the hoop is 3 kilogram and its radius...
  20. physicszilla

    Conical Pendulum with lift and tension

    Homework Statement A model airplane has a small gas powered motor in it to allow it to fly. It is tethered its controller by a long cord. The plane will fly in a circle at the end of this cord around the controller who uses the tether to control the altitude of flight of the plane. Currently...
  21. **Mariam**

    Tension of a pendulum and force components

    Homework Statement What is the tension in a pendulum? Is T=mgcos(theta) or is T=mg/(cos(theta)) ? and is the x component of tension is mgsin(theta) and this is the restoring force? Homework Equations Fnet=ma Fg=mg The Attempt at a Solution Maybe it depends on the problem given? But I am...
  22. Jordan&physics

    What Speed Makes a Pendulum Oscillate Most in a Moving Train?

    Mentor Note -- thread moved from the technical forums, so no HH Tempate is shown...>> 1. (10 points) A pendulum of length l = 39 cm is suspended in a railway car. At what train speed would the pendulum be oscillating with largest amplitude ? The length of the rails is l = 25 m. I am just not...
  23. E

    Driven simple pendulum - system of first order ODEs

    Homework Statement We have a driven pendulum described by the following differential equation: \frac{d^2\theta}{dt^2} = \frac{-g}{l}\sin(\theta) + C\cos(\theta)\sin(\Omega t) I need to turn this second order differential equation into a system of first order differential equations (then...
  24. REVIANNA

    Classical mechanics: forces on a pendulum

    Homework Statement [/B] A simple pendulum is pulled sideways from the equilibrium position and then released. I figured this part out - Immediately after the pendulum is released, the net force acting on it is directed: it is perpendicular to the string (I REASONED THAT THE DIRECTION OF...
  25. G

    Possible to derive pendulum velocity in a dynamic approach?

    Hi, Using conservation of energy $$m\cdot\ g\cdot\left(h_0-h\right)=\frac{1}{2}m\cdot\ v^2$$ it's easy to find the exact velocity of a pendulum $$v\left(h\right)=\sqrt{2g\cdot\left(h_0-h\right)}$$ at height ##h## above the minimum when it was let go from the inital height ##h_0##. Is it...
  26. X

    Lagrangian of Pendulum with Oscillating Hinge

    1.) The Problem Statement: a.) Find the Lagrangian of a pendulum where the height of the hinge is oscillating in the y direction and is is defined as a function ##y_0=f(t)## b.) Add a function (a gauge transformation) of the form ##\frac{d F(\theta,t)}{dt}## to the original lagrangian...
  27. M

    Period of small oscillations for a pendulum

    Homework Statement A pendulum consists of a light rigid rod of length 250 mm, with two identical uniform solid spheres of radius of radius 50 mm attached one on either side of its lower end. Find the period of small oscillations (a) perpendicular to the line of centres and (b) along...
  28. S

    Why is component reverse in Conical Pendulum?

    Hello. In class today, we studied conical pendulum but I was confused at the part about its components. In all the diagrams ( http://dev.physicslab.org/img/90c0fb7a-ffb4-4573-b389-b50a559732c8.gif ) if shows The x-component as being sine, but I always thought x-comp was cos?? (...
  29. whitsona

    Foucault Pendulum: How important is release mechanism?

    I built just a long pendulum in my house in order to start looking at a simple Foucault pendulum "prove the Earth moves" event at the science museum I'm helping to start here in Pensacola. It gave me a nicely reliable movement that seemed to show the pattern I was looking for. Every time, it...
  30. R

    What Happens to a Pendulum's Period at 90 Degrees Inclination?

    Homework Statement What would the period be if the pendulum had been inclined to 90 degrees? What value of g does this correspond to? theta=90degrees. Just as a side note, theta=0degrees when the arm is facing vertically downwards towards the ground. g=9.8m/s^2 Effective length=0.275m. The...
  31. tomdodd4598

    Pendulum with Pivot Moving in Horizontal Circle

    Homework Statement The problem is the following: Using a Lagrangian, find the equations of motion of a mass hanging from a massless string, with the pendulum pivot moving in a horizontal circle at constant angular velocity. I take the mass to be m, the length of the string L, the radius of the...
  32. L

    Solving a Simple Pendulum Problem with Math

    Homework Statement A 100g mass on a 1.0m long string is pulled 8.0 degrees to one side and released. How long does it take for the pendulum to reach 4.0 degrees on the opposite side? Homework Equations ##T = 2\pi \sqrt\frac{L}{g}## ##x(t) = A\cos\omega t## The Attempt at a Solution From the...
  33. TorNaGul

    What's the electromagnetic effect on a pendulum oscillation?

    Hello, This is just a curiosity of mine, after noticing light falling on a metal pendulum while doing a simple pendulum period measure, in the laboratory, using a mathematical pendulum at a small angle. Given that, there is a (very small) effect on the pendulum caused by the light falling...
  34. P

    Finding the Euler-Lagrange equation for a special pendulum

    Homework Statement Homework Equations Euler - Lagrange equation: ##\frac{d}{dt}(\frac{\partial L}{\partial \dot\theta})=\frac{\partial L }{\partial \theta}## Hamilton's equations: ##\frac{\partial H}{\partial \theta}=-p_{\theta}\text{ and }\frac{\partial H}{\partial...
  35. RMM

    How much energy can be generated by a swinging pendulum 60 kg

    I would like to make a pendulum go on moving by a permanent magnet that pushes the pendulum back with a force that is big enough to make it swing back with the same height. Can anyone tell me how much energy could be generated by a pendulum with height is 2 meter and 60 kg, swinging 90 degrees...
  36. T

    Height of Pendulum Homework: A&B Answered, C&D Yet to Solve

    Homework Statement In the two-sphere arrangement of Figure, assume that sphere 1 has a mass of 51 g and an initial height of 10 cm, and that sphere 2 has a mass of 82 g. After sphere 1 is released and collides elastically with sphere 2, what height is reached by (a) sphere 1 and (b) sphere 2...
  37. bigsmile

    Pendulum - Maximum Angle in 2nd half of swing

    A simple pendulum, 2.0 m in length, is released by a push when the support string is at an angle of 25° from the vertical. If the initial speed of the suspended mass is 1.2 m/s when at the release point, to what maximum angle will it move in the second half of its swing? Let h1 be the...
  38. M

    Mastering the Control of a Pendulum: Labview Inputs and IR Sensor Use

    Homework Statement Hi, I have a project involving an inverted pendulum, as attached. Homework Equations - The Attempt at a Solution I don't really know about some things: First, is theta the only required input from the inverted pendulum system to Labview? Don't I also need the position of...
  39. **Mariam**

    Pendulum periodic motion; period parameter

    Homework Statement A pendulum with a mass of 0.1 kg was released. The string made an angle of 7 ° with the vertical. The bob of the pendulum returns to its lowest point every 0.1 seconds. What is the period, frequency? Homework Equations T= 1/f T=sec/cycles F= cycles/sec The Attempt at a...
  40. B

    What is the Minimum Distance x for an Interrupted Pendulum to Wrap Around a Rod?

    An interrupted pendulum is one in which the string strikes a rod directly below the pivot point causing the pendulum bob to deviate from its previous circular trajectory into a trajectory of a smaller radius. Depending on the original angle of displacement θ and where the rod is placed relative...
  41. Quadrat

    Conservation of linear/angular momentum in a ballistic pendulum

    I did a problem a coule of weeks ago with a vertical rod, frictionless hanging around the upper end, length L and mass m. Then a bullet with the same mass, m speed v is fired horizontally at the lowest point of the rod and becomes embedded in the rod. So I calculated the maximum angle it would...
  42. C

    Solving for the Period of a Simple Pendulum with Given Initial Conditions

    Homework Statement [/B] A simple pendulum with l = 9.8m satisfies the equation: \ddot{\theta} + \sin{\theta} = 0 if \Theta_{0} = A Show that the period T is given by: T = \int_0^\frac{\pi}{2}\left(\frac{1}{(1 - \alpha \sin^2{\phi})^\frac{1}{2} }\right)d\phi where...
  43. D

    What angle does the hanging mass make?

    Homework Statement At a latitude of 50° north a mass is hanged by a massless string. By the means of an angle how much does the mass deviate from the Earth's radius due to rotation of the earth? Consider the Earth as a spherical body. Homework Equations Fcp=mv^2/r w=dθ/dt v=wr The Attempt at a...
  44. D

    Mathematical pendulum in a rotating plane

    Hello, I'm looking for information regarding this equation: or specifically in my case, when a=1:. This equation supposedly describes a mathematical pendulum in a rotating plane, however, I'm unable to find information on this specific subject. I'd really appreciate it if someone could show me...
  45. Y

    Lagrangian and Euler-Lagrange of a Simple Pendulum

    Homework Statement A simple pendulum with mass m and length ℓ is suspended from a point which moves horizontally with constant acceleration a > Show that the lagrangian for the system can be written, in terms of the angle θ, L(θ, θ, t˙ ) = m/2(ℓ^2θ˙^2 + a^2t^2 − 2aℓtθ˙ cosθ) + mgℓ cos θ >...
  46. H

    Bifilar pendulum experiment

    Bifilar pendulum, data matches the theory real neat. Do have a question, I would expect the period to match the period of a torsional pendulum for the limit when the support strings are the same point ie zero separation. I can't get the bifilar equation to reduce to the torsion equation for...
  47. Quadrat

    Potential energy in a physical pendulum

    Hey PF! 1. Homework Statement If I have a pendulum; a vertically hanging rod with (length ##L## and mass ##m##) which can rotate freely about a point ##p## on the upper edge of the rod. Now I fire a bullet (also with mass ##m##) into it (strictly horizontal on the lower end of the rod). I...
  48. Kernul

    Calculate Velocity & Tension of 100g Block on 50cm Wire

    Homework Statement A block of 100g is attached to a wire inexstensible long 50cm. The block is left with a null initial velocity when the wire form an angle of 90° with the vertical. Calculate the velocity of the block and the tension of the wire when the block is at the position of...
  49. applestrudle

    How do you solve this 2nd ODE for a pendulums displacement...

    ..when it is released from rest with velocity (v0, 0) I can get 1.6.5 but I can't get this:
  50. M

    How do I measure a the period of a bifilar pendulum?

    I have a formal lab due, and my idea is to use a bifilar pendulum, model its period using experimental data, and examine the effect of the length of the strings on the amplitude of the period. For anyone unfamiliar with it, here is a picture of the pendulum. This is how I plan on setting up my...
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