Pendulum Definition and 1000 Threads

  1. velocityoverrtime2

    How do I calculate the time and distance for a pendulum projectile problem?

    Tried to find time in seconds in order to use the formula d=vt and find the distance in the x plane in which the target must be placed, to no avail.
  2. S

    Spring pendulum with and without weight

    Equations provided: for a spring pendulum and m replaced with L and k with g for the same pendulum, but with no weight attached. Greetings I tried solving this by stating that the length is 0,50m (since no length of the spring is given) and turning around the equation for the spring...
  3. T

    How to Calculate Instantaneous Impact Force in a Pendulum Impact Tester?

    Hi there, First of all i want to apologize for my english, but i am not from english speaking country, so i am not perfect in it. Now for the question. I need to calculate instantaneous impact force in the lower dead center of Charpy hammer knowing nominal potential energy in lower dead center...
  4. S

    Understanding T^2 x L Graphing for Simple Pendulum Experiment

    Summary: Question regarding graphing a T^2 x L graph for a simple pendulum I did a Simple Pendulum experiment in my college physics class the other day. We were asked to graph a T^2 x L graph based off our results. I plan on using the Length on the x-axis and the T^2 on the Y-axis. This may...
  5. jisbon

    How to Apply Conservation of Angular Momentum to a Pendulum?

    So this question has something probably due to the conservation of angular momentum. I am able to find the moment of inertia about the pivot, which is : $$\dfrac {1}{3}mL^{2}+\left( \dfrac {1}{12}ML^{2}+mL^{2}\right) =\dfrac {17}{12}ml^{2} $$ Now to find angular velocity when angle =0, how am I...
  6. F

    Inverted pendulum -- What force is applied at the center of mass?

    Summary: I know that in order to keep inverted pendulum balanced when it leans forward, I should accelerate the bottom of it, but what is the force which is applied to center of mass of the pendulum with balances torque due to gravity? Is it inertial force? We assume that our inverted pendulum...
  7. F

    Segway balance question (inverted pendulum)

    Summary: Why does segway rider who leans forward when accelerating keep balanced ? Is it because the inertial torque acting on the rider balances the torque created by gravity? F=-ma
  8. F

    Solving the Rocket Pendulum Fallacy?

    I have been researching the rocket pendulum fallacy and have gotten into some spirited debate on the subject. If I understand correctly... 1. if the thrust is perfectly in line with the centerline (and no outside forces act on the craft other than gravity) it does not matter where the source...
  9. S

    What happens to a pendulum clock in a lift when the cable breaks?

    I think the answer will be either (b) or (d). If the pendulum is at its amplitude when the cable breaks, then the oscillation will stop since the pendulum is also not moving at that instant. If the pendulum is at any points except amplitude, then it will hit the ceiling since it still has...
  10. E

    Two different answers for compound pendulum problem

    I completed this problem in two different ways, and wonder why they give different answers. Firstly, I calculate the moment of inertia of the system as I = 0.572 kg m^{2}, and the total torque acting on the system as 12.152 N. Thus I can apply the rotational analogue of NII to write...
  11. Like Tony Stark

    Finding the period of a pendulum in motion along a curve

    I was solving problems about the period of a pendulum inside an elevator. They're all the same. If the elevator accelerates upwards you have that the period is shorter and it's longer if the direction is downwards. But I tried to solve something more difficult and I thought about a pendulum...
  12. Z

    Foucault Pendulum Release Velocity in Spherical Coordinates

    If the pendulum on the North pole is released to start it via burning the separation string, (to avoid adding an additional tangental force), wouldn't the pendulum at the time of release, already have a tangential velocity? does that effect the outcome of the experiment ? since the plane of...
  13. H

    How Do Coupled Adiabatic Pendula Behave?

    Homework Statement: An adiabatic pendulum (right) is coupled via a spring with spring contant κ to a normal non-variable pendulum. The pendula have equal mass m and, initially, equal length l . The right pendulum is adiabatically pulled up with frequency ω(t) 1. Derive the equations of motion...
  14. S

    Pendulum Clock -- Change in frequency with change in temperature

    1) I do not quite understand how the phrase remain accurate to 1 second in 24 hours? , means ΔP = 1 second, 2) I also don't understand how pendulum period P should be 24 hours What is the reasoning for both? The solution is as such P = 2π √(L/g) P' = 2π √((L+L α δT)/g) ΔP = P'- P = 2π...
  15. ValeForce46

    Pendulum with a mass on a container (thermodynamics problem)

    The kinetic energy of the pendulum ##K=\frac{1}{2}\cdot m\cdot v^2## will turn into heat (entirely). So both the air and the block of iron will change their temperature. To find ##n## (moles of the gas) I can use the ideal gas law: ##n=\frac{pV}{RT}=0.9 mol## Do I have the following equation...
  16. S

    Tension and speed of bowling ball pendulum passing the equilibrium position

    For part a I used conservation of energy. -m*g*cos(θ)*L+1/2*m*0^2=-m*g*L +1/2*m*v^2 => v = sqrt(2*g*L(1-cos(θ )). b) For b I was think that T = mg in the equilibrium point but that doesn't invole θ in the answer. So that's why I tought that T*cos(θ ) = mg. So that the tension is mg/cos(θ). But...
  17. dRic2

    Solve Ehrenfest's Pendulum Equation | Can't Solve It

    Well, using the above equation it should be easy... but I can't solve it :headbang::headbang: $$ L = \frac 1 2 m (\dot l^2 + l^2 \dot \theta ^ 2) - mgl(1- \cos\theta)$$ then I guess $$\int_{t_1}^{t_2} \frac {\partial L}{\partial t} dt = L(t_2) - L(t_1)$$ *Note*: since the variation ##\frac...
  18. callekula

    Question regarging pendulum axis and its motion

    Hi, I have a question regarding a pendulum and it's motion/momentum given the axis it moves around. In the below picture, there are two version of a pendulum with a weight at the bottom. It moves in and out of the screen, around an axis resting on two nails (red). My question is, how does the...
  19. Homgkung

    Can we find the frequency of a rod pendulum by just using F=ma?

    Summary: When I tried to find the angular frequency of a rod pendulum, I attempted to find its angular acceleration first, however, I realized that the results are different by using different approaches. i.e. (1) Newton's second law for a system of particles (2) Newton's second law for...
  20. michael872940

    Can I determine mass & spring k from graph of wave, t, a, & vectors?

    Classical problems for hookes law generally give either mass or spring constant. What if I have a graph of a wavelike structure that is oscillating which I can use to measure for example: T (period), t (time), Δx (displacement), v (velocity), a (acceleration) and other variables is this...
  21. S

    Direction of the net force acting on a pendulum

    I imagine y - axis is parallel to direction of A and x - axis is parallel to direction of E. There are two forces acting on the pendulum: tension in direction of A and weight in direction of D. I break the weight into 2 components: W sin θ in opposite direction to tension and W cos θ in...
  22. E

    Discontinuities in a Poincare map for a double pendulum

    I'm generating poincare sections of a double pendulum, and they mostly look okay, but some of them have weird discontinuities that seem wrong. The condition for these sections is the standard ##\theta_1 = 0## and ##\dot{\theta}_1 > 0##. Looking at one of the maps, we see that most of the...
  23. B

    Model Pendulum w/ Damping: Newton's Laws & Rubber Band

    I feel like this is a dumb question, but here goes: I'm trying to model a pendulum with damping. The pendulum is connected to a rubber band (unstretched when the pendulum is vertical) on the right side, and the rubber band is fixed at the other end. How would I go about modeling a rubber band...
  24. S

    Find the charge of a mass hanging from a pendulum in an electric field

    Hi, so I was able to solve this problem by just equating the forces (Tension, mg, and EQ). But I thought I could also solve this problem with Conservation of Energy. However, I calculated it several times, and I never get the right answer this way. Doesn't the Electric Field do the work to put...
  25. G

    Pendulum Hammer Impact Force Calculation

    Hi all, I'm a bit embarrassed but I'm extremely rusty with a lot of engineering principles. I've mainly been working in automation and controls within a manufacturing setting and have not done anything like this in ages. Anyways, I have a problem I need to solve and I need to determine the...
  26. mishima

    Sn(u), Jacobi elliptic function, for simple pendulum of any amplitude

    I understand how to reach $$\int_0^\phi \frac{d\theta}{\sqrt{1-k^{2}sin^{2}\theta}}=\sqrt \frac g l t$$ from physics but from there I don't get how to turn that into this new (for me) sn(u) form.
  27. N

    Vertical circle in a pendulum ride -- tension force acting on the gondola

    At the bottom of the circle, the tension force is greater than the weight force as there must be a net force acting towards the centre to provide the centripetal force causing the centripetal acceleration and thus the circular motion. In the equation above (T = mv^2/r + mg) I only have the mass...
  28. Miles123K

    Normal mode of an infinite spring pendulum system

    First I worked out the dispersion relations, which is pretty easy: ##M \ddot x_j = K x_{j-1} + K x_{j+1} - 2K x_j -mg \frac {x_j} {l} ## (All t-derivatives) We know ##x_j## will be in the form ##Ae^{ijka}e^{-i\omega t}## so the above becomes: ## -\omega^2M = K (e^{-ika}+e^{ika}-2)-\frac {g}...
  29. D

    Simple Harmonic motion of a Pendulum

    First, I decided to solve for the coefficient in front of the cosine simple harmonic function for velocity. I know there is max velocity of 30cm/s at time = 0 , so I plug it into velocity function. xmax * w = A v(t) = Acos(wt) 0.3 = Acos(w*0) A = 0.3 Then I have my velocity function...
  30. mishima

    Find the Lagrangian of an unwinding pendulum

    I think my confusion on this is where the best origin for polar coordinates is. I've tried the center of the circle, and note the triangle made from the r coordinate reaching out to ##m, a,## and ##l+a\theta##. Then $$r=\sqrt{a^2+(l+a\theta)^2}$$ $$\dot r = \frac {a(l+a\theta)}...
  31. EEristavi

    Linear Momentum - Bullet hitting pendulum

    Solving using Linear Momentum: M vb2/2 = M g 2L vb = 2√(g L) m v = m v/2 + M (2√(g L) ) v = 4 M √(g L) / m Note: I see from the answers - that this is correct. -------------- Next, I tried to solve it via Energy conservation point of view. M vb2/2 = M g 2L vb = 2√(g L) m v2/2 = m v2/8 + k...
  32. Celso

    Differential equation for the simple pendulum

    How do I start this? I plugged the differential equation at wolfram alpha and it semmed too complicated for such an exercise. I've also looked at a sample of an answer on cheeg where the initial approach is to rewrite the equation as ##\frac{d}{dt} (\frac{\dot\theta^2}{2}-cos(\theta)) = 0## How...
  33. Astrogirl101

    Maximum displacement of a coupled pendulum

    Hi, So I have this question to solve and I have no idea how to do it. It states: ''How are the maximum displacements of each pendulum related for ω1 and ω2? Draw a sketch that describes the motion of the system in each case. '' The 2 angular frequencies that I have found are ω1 =√(g/l) and...
  34. N

    How does Quadruple Pendulum isolate LIGO from Seismic Vibrations?

    On 28 November 2018, a lecture was given by Dr. Rainer Weiss (2017 Nobel Prize Winner for Physics) at the Ontario Science Centre, Toronto. The lecture was about his work with the Laser Interferometer Gravitational-Wave Observatory (LIGO). In his lecture talked about quadruple pendulums or...
  35. Alif Yasa

    Find the equilibrium angle of this unusual driven pendulum geometry

    -I tried to draw the forces on the hoop when it is in the equilibrium state. I know there are friction and normal force on the contact point of the shaft and the hoop -I also put the weight force to the M object -But when i used the torque equilibrium, where the pivot is the contact point of the...
  36. jaewonjung

    How does trigonometry help determine the gravity component on an inclined plane?

    Since gravity is acting downward, I found the gravity component parallel to the plane, which was g/sin60. I substituted g/sin60 for g into that equation and got D, but the answer should be C.
  37. Mason Smith

    Lagrangian and Equations of Motion for Conical Pendulum

    Here is a picture of the problem. I have chosen the origin to lie in the middle of the circle around which the mass moves. I have also chosen the z axis to pass through the origin and through the vertex of the right circular cone. The x-axis and y-axis are so that one when curls his or her...
  38. M

    Force on a pin from a pendulum and a string

    1. Determine the velocity of the ball when it is 30degrees from the horizontal: U1 = mgh = mg(0.8m) U2 = mgh = mg(0.4+0.4cos(30)) = mg(.74641) ΔU = U2 - U1 = mg(.74641 - .8) = mg(-0.051433) T1 =0 T2 = 0.5mv^2 ΔT = T2 - T1 = 0.5mv^2 ΔU = ΔT mg(-0.051433) = 0.5mv^2 ====> v = 1.025394 2. Use...
  39. C

    Find the period of small oscillations (Pendulum, springs)

    Homework Statement A uniform rod of mass M, and length L swings as a pendulum with two horizontal springs of negligible mass and constants k1 and k2 at the bottom end as shown in the figure. Both springs are relaxed when the when the rod is vertical. What is the period T of small oscillations...
  40. MathematicalPhysicist

    Friction in a simple mathematical pendulum

    How do I guarantee that that the friction in the movement of a simple mathematical pendulum is negligible?
  41. Robin04

    Lagrangian of a driven pendulum (Landau problem)

    Homework Statement There's the following problem (the task is to construct the Lagrangian) in the first Landau (part a): My problem is that I don't understand what did we omit exactly and why. Homework EquationsThe Attempt at a Solution I did the calculation myself (even checked with...
  42. astroman707

    How Do You Calculate the Electric Charge on a Suspended Cork Ball?

    Homework Statement A cork ball is suspended at an angle from the vertical of a fixed cork ball below. The mass of the suspended ball is 1.5x10^-4 kg. The length of the suspension thread is .1m. The fixed ball is located .1m directly below the point of suspension of the suspended ball. Assume...
  43. brotherbobby

    Is the Angular Momentum of a Pendulum Conserved?

    Statement of the problem : A ball shown in the figure is allowed to swing in a vertical plane like a simple pendulum. Answer the following : (a) Is the angular momentum of the ball conserved? No, the angular momentum ##L = mvl##, where m is the mass of the ball and v is its speed at an...
  44. S

    I Nonlinear Pendulum: Calculating Angular Displacement

    If I calculate the time period of a non linear pendulum using elliptical integral equation, then how can I find out the angular displacement.
  45. A

    Angular frequency of the small oscillations of a pendulum

    Homework Statement One silly thing may be I am missing for small oscillations of a pendulum the potential energy is -mglcosθ ,for θ=0 is the point of stable equilibrium (e.g minimum potential energy) .Homework Equations Small oscillations angular frequency ω=√(d2Veffect./mdθ2) about stable...
  46. S

    Pendulum Conservation of Energy

    Hi, I have a general question to pendulums. I hope it is ok to post it in this format. Please accept my apologies for my poor English. Homework Statement : As a general Example: I have a Pendulum of length L with Angle Theta as maximum displacement. I know how to solve these problems. Find...
  47. J

    Why Is the Third Pendulum Traveling the Fastest?

    You have a Photo of a pendulum with three pendulums. One is at an angle to the right the second Is straight down and third is at an angle to the left. The pengulum in the middle is traveling the greatest speed but why is the third one traveling the fastest ?
  48. A

    Pendulum & Bullet, Understanding and Applying Angular Momentum

    This took a lot of time and effort and I understand if you wish to skip past everything and just read my questions about it in the The too long didn't read summary (TL;DR) at the bottom. Homework Statement The 10-g bullet having a velocity of v = 750 m/s is fired into the edge of the 6-kg...
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