Motion Definition and 999 Threads

If an analogy is drawn to kinematics problems in which for example a ball is thrown from a height h, when it strikes the floor it has a final velocity although it stops moving instantaneously. But in this problem, the points B and D have no linear velocity when E strikes the floor. Their final...

Here is the diagram of the problem: and here is the answer of the question: What I don't understand is equation 1 and 2. The Hook's law states that F = -k(change in x) Why the change in x1 equals to x1-x2+l? x1-x2 equals to the length of the compressed spring. I cannot convince myself that...

Velocity of B wrt C = (v +v*cos 60) i^ - vsin60 j^ = (3v/2)i^-((3)^(1/2)/2v)j^ But since C is also moving this initial velocity would vary. So how to find a function which defines its path and hence I can find time at which the particles meet. I was told to take rotating frame of reference that...

I think that the only force acting on the wall is the normal force caused by Coriolis force, so it can be calculated this way: ##N=m2\dot r \dot \theta## But ##\dot r## is not constant, so how can I calculate it? Then, I can't calculate the acceleration either since I don't have the value of...

I'm not sure as to why my working is incorrect. When the sign on a_x is postive, i get t = \frac{R\omega_0}{3\mu_kg} which would give the correct value for distance if plugged into the kinematic equation. However, I'm not sure why a_x would be positive though since the friction force is pointing...

I conducted a mass-sprig experiment to see how stiffness of a spring and mass affect the frequency of oscillation. In addition to this to this i have to plot a graph to show displacement,velocity and acceleration of the mass as a function of time.From my research online For the displacement as...

Im not sure how to find k if I'm not given a force or period.

a) Alright here we have to use Euler-Lagrange equation $$\partial_{\alpha} \Big( \frac{\partial \mathcal{L}}{\partial(\partial_{\mu} A_{\nu})} \Big) - \frac{\partial \mathcal{L}}{\partial A_{\nu}} = 0$$ Let's focus on the term ##\frac{\partial \mathcal{L}}{\partial (\partial_{\alpha}...

a) 248*10^3 eV for 248kV Calculate the energy in J K=248*10^3*1.6*10^-19 =396.8*10^-19 J b) K=(1/2)mv^2 v=sqrt(2k/m) =sqrt((2*396.8*10^-19)/1.67*10^-27) =218^10^3 m/s c) r=mv/qB =1.67*10^-27*218*10^3/1.6*10^-19*1.5*10^-4 =15.17 mr=mv/qB...

Hi! This is a very simple question regarding terms of expressions. One law of motion is: F=ma Another, using L as the linear momentum, is: F = dL/dt If the first equation can be characterized (ignoring reference frames) as a "coordinate-based equation" (since is concerned with the second...

Hi guys sorry if this is the wrong thread, I have a damped simple harmonic motion pictured below, i have to find the inerval t=0 and t=1 for which the amplitude of x(t) is considered to be zero. The behaviour of the graph below can be described as e^-kt cos(2πft) k=0.7s^-1 and f= 3Hz

Summary:: We have a rotating arm, offset from the centre of rotation by a certain length, which is controlled by varying the length of a control rod. Need the angle of the rotating arm in terms of length of the rod. The blue line is a fixed column structure. CE and BD form the rotational...

Hello everyone! Let's say that you were to attempt to go as fast as possible on a spaceship with the mass of an average car in an absolute perfect vacuum. What I am wondering is, that if you were to reach a certain speed, and stop applying energy to this imagined spaceship, would the spaceship...

I my attempt, I set the drop height to 20m and using conservation of energy, i calculated the speed at the bottom. Calculating centripetal acceleration, if the radius of the circle is less than 10m then the g force is greater than 5, if equal to 10m the velocity at the top is 0 and there is 0...

f=(m v^2)/r

Besides gravity that always works perpendicular to Earth and thus pulls apples from apple trees towards the ground, there must have been some sort of mid 17th century human made contraption, that used a constant force, produced to move objects with or without wheels, in a direction parallel to...

Hi! My first question: How does he get the equation ##\frac {x_A} {2πr_1} = -\frac {θ} {2π}## ?

I intended to finish the question with the equation of linear motion with constant acceleration, but it didn't work out. And I have no idea about the t^3 and t^4 of the position. How can I find the x component of the acceleration at time 3.4 s ? Where is the acceleration rate?

I don't know how to link the x-component and y-component together.

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I attached an image

I have computed that the acceleration in my problem is a(t) = -gj - k/m(|r(t)| - L_0) * r(t)/|r(t)| Where a(t) is the acceleration vector, g is the gravitational acceleration, j is the unit vector in y-direction, k is the spring constant, m is the mass, r(t) is the position vector, |r(t)| is...

a. I tried to "rotate" the inclined plane so the surface of the inclined plane becomes horizontal h = Vi sin θi . t - 1/2 g cos ∅ t2 and when it falls to the plane, y = 0 so: 0 = Vi sin θi . t - 1/2 g cos ∅ t2 t = (2 Vi sin θi) / (g cos ∅) Is this correct?b. Particle hits the plane vertically...

Hello, I'm stuck in this rotational motion problem (advanced high school level). Source: Problems in General Physics- IE Irodov My attempt(s): First I tried using work done by the moment of friction (mgkR) and equated it with change in KE. I got the answer as ## \frac{R (\omega_0)^2}{8 \pi...

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This is a puzzle involving the orbit of the Moon around the Earth, based on the well-known story of Newton observing a falling apple and wondering if the same force that made the apple fall could also explain the motion of the Moon. The story goes that Newton considered the following: the...

in fact the answer is given in the book (written by philippe Martin). we have $$ (\tau_1| A^{-1} | \tau_2) = 2D \ min(\tau_1 ,\tau_2) = 2D(\tau_1 \theta (\tau_2 -\tau_1)+\tau_2 \theta (\tau_1 -\tau_2))$$ So $$-1/2D \frac{d^2}{d\tau_1^2} (\tau_1| A^{-1} | \tau_2) = \delta( \tau_1 - \tau_2) $$...

I am confused why the acceleration doesn't point to the center of the ellipse or one of the focus, since it moves in circular motion. Shouldn't the acceleration be just in the radial direction

I've attached my attempt at a solution below, I thought integrating it would be the best way to go but I'm just getting so confused and could use some help. This isn't my first attempt at a solution either I've been working on this for just under two hours now.

Hi all,Minimal math/physics background here, so bare with me. Imagine a smooth track or tube that tightly spirals downwards into smaller and smaller circles. Now imagine if a ball rolls down that spiral, gaining speed. At the bottom/end of the spiral the track/tube goes underneath the spiral...

I really can't figure out where to even start on this question

I am reading "Coulomb and the evolution of physics and engineering in eighteenth-century France". There it is said in page 152 para 1 that "Coulomb found that within a very wide range, the torsion device oscillated in SHM". My questions are: (1) By just looking at the time period of the...

Since given F = -kdx/dt so I equated mx'' = -kx' which gave x(t) = A + B exp(-kt/m) hence v(t) = (-kB/m) exp(-kt/m) and using v(0) = u, v(t) = u exp(-kt/m) then I...

Summary:: This is a system and we want to find the equations of motion. After some force-based attempts, I think that it would be easier to use some energy methods. Hi, I wanted to ask about deriving equations of motion by using the Lagrangian. The question is in the picture below. We are...

I would like to patch some gaps in my physics background. For example, I've been trying to come up with the sollution to the following: I have a model rigid body made up of two mass points and a massless rod connecting them. I throw the body with initial velocity under some angle of elevation...

I do not understand the following sentence (particularly, the concept of extra symmetry): 'If all ##\alpha^i## are the same, then there is extra symmetry and corresponding constants of motion'. OK so let's find the Lagrangian; we know it has to have the form: $$L(q, \dot q) = T(q, \dot q) -...

I got a confusion about the sings in the angular acceleration. When dealing with system of pulleys, how to define where is the positive and negative direction of the motion and will the choose of positive direction of angular acceleration will effect the positive direction of linear acceleration

Tell me now if this question is posted in the wrong place. This isn't a homework problem per se, it's just a question I need answered and I'm not sure how to answer it. If there is any information missing, chances are I know it and forgot to post it, so please ask if something is missing. I...

Hello everyone I was hoping someone could shed some light on the following:- I am trying to derive the equation of Momentum from Newton's 2nd Law. What I know is the following:- I don't know how to get from Force = Mass * Acceleration TO Momentum = Mass * Velocity. I have attempted to...

I am not sure which other forces I should consider besides those 3. I cannot consider tensions due to the massless rod on the masses since those will not add up to zero.

Noether's theorem tells us that an invariance of the Lagrangian yields a constant of motion. In this problem, that constant is: $$Q_v = p^a \Big( \frac{\partial q_a^{\lambda}}{\partial \lambda}\Big)_{\lambda = 0} + p^b \Big( \frac{\partial q_b^{\lambda}}{\partial \lambda}\Big)_{\lambda = 0}=...

Using A = x0, B = v0/ω I get ω = 4π, A = 1, B = 1/4π then converting to phase/magnitude form \sqrt{A^{2} + B^{^{2}}} = \alpha \sqrt{1^{2} + \left ( \frac{1}{4\pi }\right )^{^{2}}} = \alpha = \frac{1}{4\pi }\sqrt{16\pi^{2} +1} However the answer in the back of the book has α = 1 Is...

The equation of motion of a simple pendulum is: $$\ddot \theta + \frac{g}{l} \theta = 0$$ Our Physics professor told us: 'If you want to become a good Physicist you have to be able to analytically check your answers to see whether they make sense'. In class he took the limits of constant...

Please help please

Hi there I have been having a go at this question and I'm uncertain if my answer to part b) is valid? The problem is when I plug this into the calculator I get 6.379... revs however this doesn't make sense to me. 2*pi is roughly 6.28 radians so doing 4.061... rads / 6.28 rads = 0.647 revs...

Here is the problem that I am finding difficult to answer I had tried using conservation of energy to do this question Where I know that the gravitational potential energy at the top of the slope equals to the sum of both the linear and rotational kinetic energy at the bottom of the slope...

I first plugged my given values into m1v1+m2v2=(m1+m2)vf. (0.002)(600)+(5)(0)=((0.0020)+(5))vf vf=0.24 m/s Next, I plugged my given values into F=ma. ((0.002)+(5))(9.8) F=49.02 N Next, I plugged my given values into Fdeltat=mdeltav. deltat=mdeltav/F ((0.002)+(5))(0.24)/(49.02)...

I cannot figure out how to even start this.

Exercise statement: Given the action (note ##G_{ab}## is a symmetric matrix, i.e. ##G_{ba} = G_{ab}##): $$S = \int dt \Big( \sum_{ab} G_{ab} \dot q^a\dot q^b-V(q)\Big)$$ Show (using Euler Lagrange's equation) that the following equation holds: $$\ddot q^d +...

Homework Statement:: find the function of motion Homework Equations:: none i could find the amplitude and the phase angle but i can't find the phase difference and the function of motion.