Force Definition and 1000 Threads

Greetings, I am struggling with an exercise to the Langevin equation. Suppose we are given the following differential equation for a particle's 1D time-dependent momentum ##p(t)##: $$\text{d}p = -\gamma p \text{d}t + F(r)\text{d}t + \sqrt{C\gamma}\text{d}W $$ with a constant ##C##, a...

This is my attemp of solution: Since the formula to calculate the tension is T=mg I first calcualted the weight of the bridge with the ecuation W= mg m=W/g m= 18,000 N / 9.81 m/s m= 1834 kg So T=(1834)(9.81)= 17,991 N But this seems no logical to me because the Tension force is a bit less...

Hi, I have a doubt about reaction forces... I've attached a picture that shows two similar situations. The first one shows a rod left with an angle ##\beta## while it is on a smooth surface. The second one shows a rod leaning on a smooth surface and wall. My question is: why is the reaction...

I solved a and b fine, I just don't know where to start c a) i=Ft i=change in p and p=mv so i=90=45v so v=2m/s b) same thing just using the other mass i=90=70v so v=1.3m/s c) v=d/t so 1.3=d/1.5 but that would be d=1.95 and the answer key says d=.96m

I would like to undertand more the force caused by unbalance in a rotor, assume that the bearing is represented with 2 springs like above: The geometrical center of the rotor ##O## is equivalent to it center of gravity ##C_g## and the center of the stator (bearing) ##O'## The rotor is perfectly...

Hi everyone, this is my first message after presentation so please be merciful if the notation is somewhat messy. Here's my attempt at a solution: As for points 1) and 2) I used the definition of partition function $$Z = \frac{1}{h^{3N}} \int e^{-\beta \mathcal{H}} d^3p d^3q$$ and the fact that...

Hi, Hope one of you might be able to help me with some calculations :) I'm trying to calculate the amount of force required to lift an arm, based on weight, distances and angles. I made a sketch to illustrate my problem. where: Lac = Length of arm Lab = Distance from "anker-point" to...

This is a puzzle to me, time dilation seems to be stating two different times can exist (at least), i am asking if this is the case not demanding it is so, please help. I do not have a science background so i will be listening closely to what those that do, have to say. Momenta Similar to the...

Hi everyone I can't understand how normal force produce torque isn't normal force acts normally on the plane so the perpendicular distance in case if it was like block will be zero, so normal force doesn't produce torque. "case of box"

The question is to determine the force in the small opening, delivered from the 250 N on both sides of the plier. i tried multiple things but can't get the answer right. Anyone that could help me? This is my work so far:

Free body diagram one each object: Block 1: Normal force upwards, weight downwards, tension to the right, friction to the left Block 2: Normal force to the right, tension upwards, weight downwards, friction upwards Cart: Contact force with block 1 downwards, contact force with block 2 to the...

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

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...

I found the steady state solution as F_0(mw_0^2 - w^2m)Coswt/(mwy)^2 + (mw_0^2 -w^2m)^2 + F_0mwySinwt/(mwy)^2 + (mw_0^2 -w^2m)^2 But I'm not sure how to sketch the amplitude and phase? Do I need any extra equations?

Is there any astronomical indication that gravitational force between dark matter might be weaker than between visible matter?

Summary:: I try to find the resultant force on "q". I think I have to find the value of Q, but I'm not sure. I Know F1 = k|q * 2Q| / 3² and F2 = k|q * Q| / 2² Hi, this is my first post on this forum I hope I posted in the right section. I try to find the resultant force on "q". I think I...

As I have shown in the picture even if their is minimal change but shouldn't it increase after a long time as minimal changes will keep accumulating.

Source: Principles of Nano-Optics, for Lukas Novotny and Bert Hecht.The equations above represent the electric field in the second medium when a light hit a surface and the condition of TIR (total internal reflection) is satisfied. Actually this is what called Evanescent field. The point is if I...

I calculated the potential energy of the particle as follows : But I am not sure how to calculate the kinetic energy. I know that if it was a satellite orbiting a Earth, I could use ##\frac {GMm} {r^2} = \frac {mv^2} {r}## to calculate the velocity v and they I could calculate kinetic energy...

Hello; What equations on mechanics can I use or study in order to measure the maximum force in Newtons the surface of the metal Steel box can hold. Details: Watch the image below, we have a metal box made of let's say steel, this box have a shape of rectangle of a thickness of for example 1cm...

Okay let's say we have a wheel attached to a fixed axle, free to spin, ignore friction and we apply a force on the edge of the wheel. That force creates a torque, does the axle have an opposing force to keep the wheel/axle assembly from accelerating linearly? Ive learned on this forum that when...

Why does the force due to surface tension act parallel to the surface here? I know that surface tension is a result of absence of cohesive force above the surface and thus the water molecules below pulls the surface down and keeps it like a stretched membrane. If the surface is pressed as...

When I blow a balloon with CO2, it falls as it is heavier than air. Then it is gravity that causes the balloon to fall. When I buy a balloon filled with helium gas from a store, it floats as it is lighter than air. But what force is causing the balloon to float?

I want to focus this question on understanding the force ##F(r)## I get (thus, I want to focus on c) ). However, below the dashed line, I included steps on how I derived ##F(r)##. We are going to work in polar coordinates. Knowing that the acceleration is: $$a = \Big( \ddot r - r \dot...

Hi, I am trying to find out Force on a rigid body when it is completely inside a fluid with density p, i.e. the body is completely drowned in the liquid and then another liquid is pushed into the container with different density 'r' (such than r > p). Thanks.

Background: My understanding is force and mass are two different things. Mass is how much matter is in a body Force is mass multiplied by an acceleration. Here on earth, that acceleration is 32.2 Ft/s2. Therefore, for the same mass, there can be different forces depending on the...

I solved this question until the end of the "c)Find the distance until the boat completely stop" However I can not solve the integral I encounter in the solution of the last part of c). Would you please check for math and maybe my mistakes and tell me what to do? Here:

I believe I solved this. Is this solution true? Can please anyone just check?

Good afternoon, I have some doubts about the tension force suffered by a spring to which a mass is hung and which is making a simple vertical armoin movement. My doubt lies in the fact that at the bottom of the pier (where the mass hangs), the spring exerts the restoring force that is given by...

ans is opt4

I tried solving the differential equation by integrating both sides wrt t but this does not work out and I am doing something wrong. How do I integrate such an equation properly? d²x/dt² = -k²/x³ => dx/dt = -k²t/x³ => x = -k²t²/2x³ + d

I got this picture from a superconducting parametric amplifier text I was reading. (The picture is a mechanical analog of a non-degenerate parametric amplifier.) If the balls(red and blue) were oscillating at their own natural frequencies, and an external force is driven(purple), how would the...

lets say a hammer of 0.5kg strikes a nail at 10m/s. The nail penetrates into the wood by 1cm. The reason why the nail stops is because friction has eventually overcome the nails momentum. The retardation of the nail can be worked out, but Can you calculate the force that stops the nail if you...

Summary:: Calculating the inclination angle A stick is on two springs with spring constants D1=500N/m and D2=300N/m. Consider the stick is without mass and can rotate around the point E, which is distant from spring 1 with 0,1m and from spring 2 with 0,8m. A force F=100N pulls the stick up...

I'm sorry but I can't even attempt this question since I'm pretty much clueless, I got the notes but I don't understand them.

I've been working on this problem for a couple days now and I'm clearly missing something. I first went ahead and solved the triangle. Hypotenuse is 5, height is 4, the last side is 3 and the angle is 53 degrees. I went ahead and did the sum of forces in the y direction = Fn - Fbucket - Fearth =...

μThe magnetic field is supposed to be B=μ0i/(2πr). I think that the force would be aimed upwards. Now I tried to divide the wire BC to infinite smaller wires where B is roughly constant in each one of them. What I get is: However this is not correct when I plug the relevant numbers in it...

How to find potential energy if force depends on both position of particle and time ? Suppose force is : f(r,t) = (k/r^2) * exp(-alpha*t), k, alpha = positive constants, r = position of the particle from force-centre t = time Is this force a conservative or non-conservative ?

Hello all I am trying to find the hydrostatic force of a cylindrical tank of water. I was hoping someone could help point me in the right direction. I have a cylindrical water tank. The dimensions are as follows:- I need to find the magnitude of the hydro static force per unit of...

In Einstein's theory, gravity is caused by the warping of spacetime. This leads some people to object to gravity being referred to as a force. However, to me it is correct to say that a paperweight resting on a desk is exerting a force on the desk (and vice versa). Is this a correct statement...

hi, I have read that the process of repulsion between two similar charges, such as two electrons, is mediated by the exchange of a photon. This photon somehow merges with the nearby electron and somehow directs the electron to move in the opposite direction. Is this correct? I don't quite...

The figure is in the attached image. My attempt: I(wheel-disk system) = 0.5mr^2 + MR ^2 = 0.5(0.2kg)(0.1m)^2 + (1.5kg)(0.3m)^2 = 0.136(kg)(m^2) Fnet(of object) = Ma Mg - T = Ma T = Mg - Ma Fnet (wheel-disk system) = (M+m)a Mg- Ma - Fr = (M+m)a a = 0 because system in equilibrium Mg -...

Hi Guys, I am trying to keep this as simple as possible as I only need a ballpark figure. I am sure there are thousands of other variables which need/could be taken into account, but for this purpose, as simple as could be. A door in my house slams when other doors/windows open. The door is...

Hi, I have a simple question but I want to be 100% sure that my reasoning is correct. Take a look at this picture showing forces acting on an airfoil: Green forces (X and Y components) are known from CFD software but I need the values of blue components (lift and drag). Of course for zero...

Hello all I was hoping some could help shed light on the idea of a Point Of Action of a force. I have a rectangular wall of 32m which is holding back water, the water is at a height of 29m. Where is the point of action of the force? The problem is illustrated below:- I have been told that...

When is weak interaction actually a force, rather than merely cause of some process? Not in beta decay - it is process. There are simpler weak interaction processes around: elastic scatterings that change only momentum but not taste. But those are still processes and are over as the particles...

Hello, Just refining my understanding of the work-KE theorem and seeking some validation: The work-kinetic energy theorem states that the mechanical work done by a force (be it conservative or nonconservative) is always equal to the change in kinetic energy of the body. The net force in a...

Hi All We know that beta decay is and ejection of an electron from nucleus, making a proton turn into a neutron (and a neutrino). Is it correct to say that is the weak force responsible for the increasing in the distance between electron and proton during this process (since the feel atracked...

I need to conduct an experiment and measure how what is the coefficient and force of friction of the rubber that pushes down along the edge inside the syringe. The thing is I can’t use a dynamometer.