Vibrations Definition and 236 Threads

Could someone please help me get a very basic intuitive understanding of what rotational and vibrational quantum numbers mean? For simplicity, assume a diatomic molecule. For example, does a higher rotational quantum number mean that the molecule is rotating faster? Is the vibration number a...

Homework Statement A spring, of negligible mass and which obeys Hooke's Law, supports a mass M on an incline which has negligible friction. The figure below shows the system with mass M in its equilibrium position. The spring is attached to a fixed support at P. The spring in its relaxed state...

Is it possible to predict theoretically the maximum amplitude of vibration that atoms of a metallic species, like Copper, will exhibit at a given temperature?

Homework Statement For the hoisting mechanism shown, what is the static stiffness (N/m) at point A, in the vertical direction? Assume the beam and rope materials are linearly elastic. Homework Equations You can make progress by starting with the definition of stiffness, being the...

Can Wilson's GF (FG) Matrix Method be applied to linear molecules as well as nonlinear? For example, can it be applied to a linear chain of hydrocarbons? What are some of the restrictions?

What do i and j stand for here? My teacher substituted them for masses (in our example, atoms in a molecule) although I'm not sure that makes sense since when you take the Hessian force constant matrix (on the next page of the link) I believe it must have dimensions determined by the number of...

Homework Statement A thin beam of length L (flexural Stufness EI, cross-sectional area A, density p) is connected to a linear spring of stiffness K_s at each end. Derive the governing equation for the natural frequencies of transverse vibrations from the beam equation and boundary conditions...

Homework Statement A cord of length L density p and cross-sectional area S is under tension T with the left end fixed and the right end attached to a spring-mass sstem. Show that the equation for the natural frequencies is given by: tan(wL/c) = -(T/kL)((wL/c)/(1-(w/w_n)^2)) Homework...

Hi, This is second week of our class, despite understanding what is being taught or being assigned to read, I'm having troubles with homework...it's taking too long. Our professor gives out challenging problems (or so the other classmates say), however i think i could work them out...

Homework Statement Prove that the equation x(t)=e-ζωnt(a1ejωdt+a2e-jωdt) is the same as x(t) = Ae-ζωntsin(ωdt+φ) Homework Equations Refer to the first question's answer. The Attempt at a Solution Have no idea how to start this problem. That is probably because I am low on funds and...

hi i am a final year mechanical engineering student. For my final year project i have been given a project where i conduct experiments on a punchbag using sensors(accelerometers) and masses to strike the punchbag. Then using dynamics and vibrations analysis i should be able to calculate the...

Homework Statement this is part of a problem sheet and is the last question i have left to work out. i have been given solutions of 105dB and 86dB. A person is in a room in which two sources of sound of loudness 100 dB and 98 dB are emitting the same frequency. The sources form a...

Hi I have a problem in detecting whether string is vibrating or not. I'm going to conduct experiment which will investigate impact of different factors on time of decaying of guitar's string oscillations but I have no idea how to measure when oscillations stopped. Acoustic method doesn't work...

Hi people, I have a question which i hope you helpful guys/gals can help to shed light on. We all know when we strike one end of a solid metal rod with a hammer sideways (i.e. from left to right), longitudinal vibrations will be set up across the length of the rod. Textbooks and websites...

Homework Statement The disk, hvng a weight of 15kN, is pinned at it center O and supports the blck A that has a weight of 3 kN. If the belt which passes over the disk is not allowed to slip at its contacting surface, determine the natural period of vibration of the system. Homework...

Can EM waves falling on a solid contribute towards lattice vibrations? If yes, then i)when is the energy used in lattice vibrations, ii)when is it used in excitation of electron into higher energy level, and finally, iii)when is the energy utilized for slight vibration of the electron...

Homework Statement A mass m=4 is attached to both a spring, with spring constant k=37, and a dash-pot with damping constant c=4. The ball is started in motion with initial position x0=1 and initial velocity v0=8 . Determine the position function x(t). Homework Equations The...

Vibrations and waves 1) A 5 kg mass, m, rests on a frictionless, horizontal, wooden table top, and is attached to one end of a spring anchored at its other end . If the spring has a spring constant=13 N/cm and the mass is pulled back (in the positive direction ) 20 cm and released, to the...

1) A 5 kg mass, m, rests on a frictionless, horizontal, wooden table top, and is attached to one end of a spring anchored at its other end . If the spring has a spring constant=13 N/cm and the mass is pulled back (in the positive direction ) 20 cm and released, to the nearest tenth of a joule...

Waves and Sound Vibrations Question Urgent Please Help?? Homework Statement A mass suspended from the end of a spring vibrates up and down 25 times in 50s. What ar ethe frequency and period of the vibration. Homework Equations F = 1/T T = 2(pie)3.14(squrroot)L/g The Attempt at a...

Vibrations Assignment Please Help! Homework Statement A pendulum takes 0.5s to swing from its hgihest point to the equilibrium position. What is the frequency of the pendulum? Homework Equations f = 1/T The Attempt at a Solution So would it be this? f = 1/T f = 1/0.5 f = 2Hz

Frequency of a Car's Vibrations? Homework Statement When four people with a combined mass of 297 kg sit down in a car, they find that the car drops 2.8 cm lower on its springs. Then they get out of the car and bounce it up and down. What is the frequency of the car's vibration if its empty...

Homework Statement I'm trying to do some numerical stuff with vibrations of H20 and I'm working in mdyne, angstroms, atomic mass units, and angles are given in radians. What would the corresponding unit of time be when I calculate my normal mode frequencies? femtosecond, 10e-15?

Homework Statement Assume that the differential equation of a simple pendulum of length L is L\Theta'' + g\Theta=0 where g=GM/R^2 is the gravitational acceleration at the location of the pendulum. Two pendulums are of lengths L1 and L2 and when located at the respective distances R1 and...

This is for a vibrations course. A force F(t)=Focos(w*t) is applied to a point on a spring located 25% of its length from the fixed end (at the ceiling). I am trying to write out Newton's 2nd for the block. This requires that I find how much of F(t) is transmitted to the block. I am a little...

Homework Statement Tension is maintained in a string as in the figure. The observed wave speed is 26 m/s when the suspended mass is 3.2 kg .What is the mass per unit length of the string? The acceleration of gravity is 9.8 m/s2 . Answer in units of kg/m The Attempt at a Solution can...

Hello everyone, I am a junior Mechanical engineering student with a midterm in my Vibrations I class on Thursday. I've been studying but I'm having some issues really nailing the concepts fundamentally. I feel like I'm stuck in a rut of doing the problem like in the example, but not really...

Homework Statement A front-loading washing machine is mounted on a thick rubber pad that acts like a spring; the weight W = mg (with g = 9.8 m/s^2) of the machine depresses the pad exactly 0.19 cm. When its rotor spins at ω radians per second, the rotor exerts a vertical force F0=cos(ω*theta)...

Is it possible to determine the actual number of vibrations associated with a given photon? Do all photons from similar events have the exact same number of vibrations? For example, do all photons resulting from electrons dropping from the next to the lowest level to the lowest level in a...

Homework Statement A mass m is attached to a spring(massless) that is located inside a massless box. The box is falling under gravity. When the box starts to fall the spring is in it's equilibrium position and the box sticks to the ground when it hits it. -The box is a distance H from the...

I am looking at forced vibrations and I have come across this: (w_max)^2 = (w_0)^2 - (1/2)y^2 Now I am not entirely sure of what the (w_max) is. ANd where does this equation come from? It was simply stated without a derivation. THanks guys!:biggrin:

Hi, I don't understand how to go about solving a problem like this; A weight stretches a spring 3 inches. It is set in motion at a point 4 inches below it's equilibrium point with zero velocity. -Find the maximum amplitude -When does it reach (the first time) it's highest point -Find...

I appologize in advance if this problem will be awkwardly presented, but I'm a biologist, with no talent for physics or mathematics whatsoever. Here goes... At my institution, we are researching communication of certain bugs, which use low-frequency, substrate-borne vibrations as signals...

Homework Statement A 30-cm long string, with one end clamped and the other free to move transversely, is vibrating in its second harmonic. The wavelength of the constituent traveling waves is: A) 10 cm B) 30 cm C) 40 cm D) 60 cm E) 120 cm Homework Equations L =...

Homework Statement A standing wave is established in a 120-cm-long string fixed at both ends. The string vibrates in four segments when driven at 120Hz. (a) Determine the wavelength (b) What is the fundamental frequency of the string? Homework Equations (a) Lambda = 2L/n The...

Homework Statement a bloc of mass m=175,5 kg is supported by 2 springs K=k/2 = (unknown) and a damper c (unknown). see vibrations.bmp at 950 RPM, a stroboscope shows that the excentric mass is at his highest and the mass m is at equilibrium position with an upward velocity. amplitude of...

When setting up this derivation one assumes a chain of identical atoms. The interatomic interaction between atoms is short ranged and so only affects neighbouring atoms (see Hook and Hall, "Solid State Physics" chapter 2.3.1). The potential V(r) is expanded as a taylor series about r = a to...

suppose you have a system Ma + Kx = 0 for some nxn matricies M and K assuming a harmonic solution of the form a = -w^2*x will, in principle, allow calculation of the natural frequencies based on the characteristic equation, and calculation of the corresponding mode shapes. It's my...

Homework Statement Translated from swedish so i hope i get it right... Observe vibrations along the axis of the bond in a hydrogen molecule (H2). For low temperatueres, by which factor does the rms value ("root-mean-square deviation") of these vibrations amplitude change if one of the...

Quote from Organic Chemistry, L.G. Wade, Jr.: "Not all molecular vibrations absorb IR radiation." "One of the component of an electromagnetic wave is E field. This field alternately stretches and compresses a polar bond." "If this alternate stretching compressing of the bond occurs at the...

Homework Statement A spring-mass system has a spring constant of 3 N/m. A mass of 2 kg is attached to the spring, and the motion takes place in a viscous fluid that offers a resistance numerically equal to the magnitude of the instantaneous velocity. If the system is driven by an externam...

[SOLVED] Sound waves and vibrations I read a post here on PF dated back in Nov 2003. 'Security' needed some help with his Physics exam... and what a coincidence! I'm also working on that same exam now. PF Admin 'chroot' helped him with the questions... and I got confused with some of his...

Homework Statement A guitar string is set in vibrations at a frequency of 437 Hz. How many vibrations did the guitar's string make while the sound propagated 235 m in the air? Homework Equations V = wavelegth x freq. The Attempt at a Solution I figured out that you do 437 Hz x...

Vibrations and Waves - please help! I'm having trouble with my physics homework. I can't seem to figure out which formula to use to solve a particular problem. "If a particle undergoes SHM with amplitude 0.25m, what is the total distance it travels in one period?" The formulas I have that...

somone could help me to know how to find the normal vibration coordinate of the A1 representation in terms of the coordinates x,y and z of each atomes ( given: we take the carbone atome as a center of the x,y and z axis ).

Homework Statement http://img240.imageshack.us/img240/790/imgso5.th.jpg A hoist mechanism is modeled as shown in the figure. The drum is driven through a gearbox, the mass and flexibility of which is modeled as shown. The load required to be lifted and the cable stifness are also given. Choose...

Homework Statement A 7 metre long string is stretched between 2 walls so that its ends are fixed. It is made to vibrate and it is found that the displacement, y is given by: y = 0.023sin(xpi)cos(0.714 pi t) where x and y are in metres and t is in milliseconds. a) to which harmonic, N, does...

I have all of the my work and answers, I would just like someone to look over what I've done and make sure I didn't fubar a step along the way. Thanks. 31. Given: A = 1.12 mm; f = 440.0 Hz Find: v_{m}, a_{m} Solution: f = \frac {\omega}{2\pi} \Rightarrow \omega = 2\pi f v_{m} =...

Homework Statement Hello everyone, I'm a bit stuck on this particular problem and i was hoping somebody could give me a couple tips or hints! "consider a linear monoatomic chain where all atoms have a mass M except one which has a small mass m. The force constant is C." First I'm asked...

Hello, I have almost got my degree in computer science but I’ve got a little problem and I need some help with an assignment. The assignment is in the fields of Physics (Vibrations and waves: Feedback control and oscillating conditions) and is an essay. The reason I ask for help is that I have a...