Dynamics Definition and 1000 Threads

My son today asked me for an analysis of a situation, which was described to him as being purely anecdotal but apparently a fairly widespread belief among bartenders, so possibly correct. The description is that if you take the two metal halves of a cocktail shaker, with a normal compliment of...

Currently working through some exercises introducing myself to quantum field theory, however I'm completely lost with this problem. Let $$L$$ be a Lagrangian for for a real vector field $$A_\mu$$ with field strength $$F_{\mu\nu} = \partial_\mu A_\nu - \partial_\nu A_\mu$$ gauge parameter...

Homework Statement As shown in image. 2. Homework Equations Moment of inertia of pulley = 1/2*M*R^2 Moment of inertia of rod (about end) = 1/3*M*L^2 Acceleration of end of rod in theta direction = L*α Acceleration of end of rod in radial direction = L*ω^2 The Attempt at a Solution...

To start this question off, I'll just state what I do understand about potential flow theory 1.) I understand that the navier stokes equations are really difficult to solve analytically except in degenerate cases where the assumptions about the flow cancel out the non-linear terms. 2.) I...

Homework Statement This is not a set question but a problem statement for an investigation. I am trying to understand the physics behind drinking through a straw, but not when the straw is fully submerged in the drink but at the end of the drink when the liquid and air both pass up the straw...

In my rough understanding Molecular Dynamics using Classical Newtonian mechanics is a 6N dimensional non linear system. 6N dimension because you have 3 position vectors and 3 momentum vectors for each N particles. Nonlinearity because of the terms in force fields. In principle this system can...

<< Mentor Note -- poster has been reminded to fill out the Attempt at the Solution part of the Template in future HH threads >>[/color] 1. Homework Statement An object of mass m is at rest at the top of a smooth slope of height h and length L. The coefficient of kinetic friction between the...

Homework Statement Homework Equations xf = x0 + v0cos(θ)t + (1/2)axt2 yf = y0 + v0sinθt - (1/2)gt2 F = ma The Attempt at a Solution [/B] I first tried to find the acceleration in the x direction so I could solve for the force xf = x0 + v0cos(θ)t + (1/2)axt2 In order to find the time I used...

Homework Statement When an applied force elevated at angle θ is used to drag mass m along a surface with μ as the coefficient of friction, the mass accelerates horizontally with some value, a. Derive the cleanest and most simplified formula for the applied force, Fapplied, that will give the...

Imagine that we wanted to build a slingshot, using one piece of rubber attached to two hooks - each on a side. We use a rubber, whose spring constant is k. My questions are: 1. If we began to string that slingshot and the rubber would begin to fold, what would happen with the string...

my first post having just joined! Problem statement - what curve describes the surface of a rotating liquid? Stirring my cup of coffee years ago sparked this thought. Question - is the way to solve this problem to use variational calculus, or fluid dynamics? I have always thought the former but...

Homework Statement On a train, there is a passenger who has an aquarium, filled with water. The aquarium's size: 40cm x 25cm x 25cm, and is filled with water up to the height of 20cm (5 cm remaining) What is the maximal deceleration of the train, such as the entire volume of water will remain...

How would one calculate the drag on a projectile (in this case a 1cm3 cube) that was launched at 0°. The vertical drop, initial velocity, distance, and time (taken to travel distance) where measured. I want to say that I could compare these experimental drop (bellow hight that projectile was...

Homework Statement I've been looking at examples of motion derivations for my class, and it's honestly just very confusing. I heard Dynamics should prep you for this but I must have had a very poor course because we never had to understand geometry and physics to this degree... Homework...

Homework Statement A car enters a turn whose radius is ##R##. The road is banked at angle ##\theta##, and the coefficient of friction between the wheels and the road is ##\mu_s##. Find the minimum and maximum speeds of the car to stay on the road without skidding sideways Homework Equations...

Homework Statement Homework Equations U = 1/2 kx2 The Attempt at a Solution So, I took dynamics off campus and needless to say, we didn't really do very much deriving so that aspect of physics really bogs me down and I'm trying to learn it now in another class. So if anyone wants to also...

Homework Statement Homework Equations d/dx The Attempt at a Solution d/dx (T) = d/dx(1/2mx'2) = mx'' d/dx(U) = d/dx(1/2kx2) = kx' ≠ kx It's probably me who made an error because I know that that equation (2.3) is the one I should be getting, but I don't understand how they did it because...

Homework Statement A uniform bar with length c can slide a cylindrical surface with a radius of r. Determine the maximum angle theta that guarantees the equilibrium of the bar if the friction coefficient at the points of contact is u. Homework Equations Friction force = u*N (where N is the...

Hi! I am new to this forum and i have problem understanding sample problem 13.5 from Vector Mechanics for Engineers 10th edition Statics and dynamics. (Beer) In particular I don't understant how in part b assigns the value aC=-1/2aD If anyone can help thanks

Homework Statement A 500 g block lies on a horizontal tabletop. The coefficient of kinetic friction between the block and the surface is 0.25. The block is connected by a massless string to the second block with a mass of 300 g. The string passes over a light frictionless pulley. The system is...

Is the capability to apply force dependent on the medium.Suppose two human beings are placed in vacuum.Now, can they apply forces on each other? Also, can force fields such as gravitational and electrical fields exist in vacuum and if so then why?

If you hit your feet or arms on hard object like corner of furniture.. you know it would form bruishes that turn bluish color days later.. but is there any advantage if you can avoid its formation by using ice or any med that can avoid the formation of the bluish colors later?

As part of a racing community, there is a discussion going on that talks about compressibility of brake fluid. the Street car versions have a value of 6.5E-05 and the racing stuff is 4.5E-05 both at a pressure of near 5000psi. there is talk about the difference of the racing fluids which...

Homework Statement A sleigh with a mass of 150 kg from rest is horizontally towed to the left . This is done using a rope that makes an angle of 30 ° with the horizontale. The tensile force is 200 N. (Neglect friction forces.) a. What is the horizontal component of the force? b. What...

Homework Statement A skier glides down a slope, and has at the bottom of the slope, at the beginning of a horizontal piece, a velocity of 30 m / s. He begins to brake and after 4 seconds later has a speed of 10 m / s. The friction between the skis and the snow is 400 N during braking. a. What...

Imagine thee planets interacting through gravity, mathematically how should they come and rotate in a same plane, like planets and sun?

I'm making a vibration rig that represents a classic 2 mass, 3 spring system (See attached Image). (To clarify the image - there will be no forcing frequency. m=m1=m2 and k=k1=k2=k3) I'm using extension springs in the vibration rig. I plan to displace them in extension at an equilibrium point...

Homework Statement A water bottle has a tap tube at the bottom. The diameter of the valve opening is 1 cm. If you turn on the tap, the water drains out with a velocity of 1.4 m / s. If the air pressure in the bottle is equal to the atmospheric pressure outside it, how high the water than in the...

Homework Statement Through a (cylindrical) heating tube, warm air has to flow with a velocity of 3m/s in order to heat a rectangular spacewhich is 12 m long, 10 m wide and 2.5 m high. How large the radius of the tube should be if the air in the room get refreshed every 15 minutes ? Assume that...

Homework Statement A light string is passed over a pulley and two masses m1 and m2 are suspended from the two free ends. The pulley is a uniform circular disc of mass M. Find the linear acceleration of the two masses. Friction may be neglected. Homework Equations I through center of the disc =...

Homework Statement Homework Equations F=m*a ΣF(n-direction)= m*a(n)= m*(v^2/ρ) ∑F(t-direction)= m*a(t)\ Ffriction= Fn*coefficient(of friction) The Attempt at a Solution So I tried solving this question and apperently it is way easier than I thought. So I thought the kinetic friction has a...

Homework Statement A uniform bar AB of length L is freely hinged at one end A and released from a horizontal position. a) Find the initial angular momentum. Ans: 3g/2L b)Find the angular velocity when the bar is vertical. Ans: (3g/L)^(1/2) Homework Equations momentum of inertial of a rod...

I work with an electromagnetic molecule trap, and I'd like to determine which orbits are chaotic. To this end, I intend to study the evolution of a perturbation on a trajectory with time. I'd like to compute something called the fast lyapunov indicator for various trajectories y(t), where I...

Homework Statement Homework Equations f=m*a V= Vg*cos θ The Attempt at a Solution Is this solution correct. I did everything the same, but I did not use the 15 ft/s. Since An= (v^2/ρ) with V being the velocity in the t direction. The 15 ft/s according to me is only the component of V that...

Homework Statement Deduce, from the equations employed in Q4 and Q5, the exponent n in the equation: T = k rn where k is a constant and T is the period of a satellite which orbits at a radius r from a massive object in space. Hence, how long is the “year” on Venus if its distance from the Sun...

Homework Statement Homework Equations F=m*a The Attempt at a Solution Don't worry it not a homework question of mine. I was just trying to solve some questions (on my own) that I know I have difficulty with to get better at it. Especially with springs I can get confused, so I thought I...

Homework Statement A block of mass 5 kg rests on a wedge placed on a table. The mass of the wedge is 10 kg. The wedge has an incline of angle θ = 30 degrees. a) Find the normal reaction of the table acting on the wedge. ANS : 150N b) Repeat (a) if the block slides down the wedge without...

Hello! Please help me understand whether I'm going to the right direction with the solution or partially wrong or completely wrong. I have a basic Fluid Mechanics course at the uni, the following problem is from a past exam my teacher gave us to practice before the exam, so there're no answers...

Im starting to learn about vehicle dynamics by watching video lectures here , and also reading the books by Gillepsie and Jazar. I´ve got a fundamental question about the FBD of the vehicle. According to Gillepsie :http://imgur.com/a/lGXxw http://imgur.com/a/lGXxw The vehicle is...

Homework Statement The 2-kg collar C is free to slide along the smooth shaft AB. Determine the acceleration of collar C if (a) the shaft is fixed from moving. (b) Collar A, which is fixed to shaft AB, moves downward at constant velocity along the vertical rod, and (c) collar A is subjected to a...

Homework Statement Two cardboard boxes full of books are in contact with each other on a friction less table.Box H has twice the mass of Box G. If you push on box G with a horizontal force F, then box H will experience a net force of? 2. The attempt at a solution Let book G's mass be = m...

Hi All, So glad to have come across this amazing site and resource. I am a mature student completing an engineering degree with the Open University and I am after some guidance and help with creating a way to plot forces from a moving mechanical system. The images on the attached drawing are...

Homework Statement part(b) and (c) Homework Equations Conservation of momentum Conservation of angular momentum Conservation of mechanical energy The Attempt at a Solution So first I thought that I could do it by just using the conservation of mechanical energy, but then I realized that since...

Homework Statement Two football players separated by 42m run directly toward each other. Football player 1 starts from rest and accelerates at 2.4m/s^2, and football player 2 moves uniformly at 5.4m/s. How long does it take for the players to collide? Given: player 1: v1=0m/s, a=2.4m/s^2Player...

Homework Statement Homework Equations i) F=ma=mv/t ii) E=mv2/2 The Attempt at a Solution Now based on equation 1 , I have concluded that the velocity gained is inversely proportional to m, and that so is the kinetic energy , I have seen otherwise.[/B]

I am using Jose & Saletan's "Classical Dynamics", where they introduce a rather contrived Hamiltonian in the problem set: H(q_1,p_1,q_2,p_2) = q_1p_1-q_2p_2 - aq_1^2 + bq_2^2 where a and b are constants. This Hamiltonian has several constants-of-motion, including f = q1q2, as can be easily...

So I'm trying to understand Newton's laws, and I know that friction is supposed to be the force that stops an object in movement. But I don't really understand why this is the case, as the force of friction is not something that can be perceived intuitively (unlike, for example, the force I...

One end of a thin, uniform rod is connected to a frictionless hinge as shown in Figure 1. The rod has a length of 0.8 mand a mass of 2 kg. It is held up in the horizontal position (θ=90∘) and then released. 1)Calculate the angular velocity of the rod at θ=90∘. 2)Calculate the angular...

Long story short. Want to know waaaay before I get deep into Aerospace Engineering, what I need to know to do it and if I can, I've already retrieved books on it. Like Fundamentals Of Aerodynamics... Some Calc 2 books.. Calc 1.. etc etc. However I look at Calc 1/2, then look at my Aerodynamics...

Hello here is a schematic of the problem: http://imgur.com/CgcybVT A stream of helium gas will be used to carry aerosolized particles. I am assuming conservation of mass (and mass flow) The mission is to find the exit stream velocity of the gas. For the time being, i am assuming the weight...