Forces Definition and 1000 Threads

r_{13}=r_{23}=\sqrt{(30*10^{-3})^2+(90*10^{-3})^2}=\sqrt{9*10^{-3}}\\ F^E_{13}=F^E_{23}=9E9\cdot\frac{5*10^{-9}\cdot3*10^{-9}}{9*10^{-3}}=1.5*10^{-5}\\ \theta=tan^{-1}(\frac{90*10^{-3}}{30*10^{-3}})=71.565\,degrees\\ \vec{F}^E_{13}=<F^E_{13}cos\theta, F^E_{13}sin\theta> = <4.743*10^{-6}...

If you do the sum of vertical forces and sum of moments, you're always left with an unknown. Vertical Forces: Ray + Rby + Rcy = 59kN + 45kN (1) Sum of Moments about A: (59 x 1.85) - (Rby x 3.7) - (Rcy x 4.8) + (45 x 6.5) = 0...

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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...

I am hoping a PF participant can help me understand why the tidal forces cause the NGTS-10b planet to fall towards it's star. I more-or-less understand why our moon's tidal forces on the Earth cause the Earth's rotation period to decrease, and the conservation of angular momentum of the...

I literally don't know where to start with this, i drew a free body diagram to try and understand where the cylinder was affecting them, but it didn't get me anywhere

Hello everyone, someone could explain me please, why the work of the normals forces are 0 ? He used with conservation energy equations. How should I refer to the displacement point ? Thx everyone !

The correct answer is the second one. I honestly have no idea why this is so. I understand that the right rope has less tension that the left one since it's at a shallower angle from real world experience, but I don't really know why this is so, let alone how the forces compare to gravitational...

If route perpendicullar forces supose to have no affect, why isn't this the case when somebody tries to cross a river? the motion is perpendicullar when water speeds aprox. at the same direction.. what am i missing?

So there's something I'm missing when I think of Newton's 3rd law of motion. If all forces between two objects exist in equal magnitude and opposite direction, how is it that, for example, when I'm driving my car, the car "runs through" all the air molecules, and they seemingly don't exert the...

Hi, Here is a multiple choice question I am stuck with and would appreciate some guidance: The mark scheme for this paper says it is option A - 0N. I didn't get that at all. If a current carrying wire is in a magnetic field with some component perpendicular to the field then how can it be...

I was seeing a video about molecular orbital theory..at t=3:56 he counted the forces but I don't why he didn't considered repulsions between electrons. Please can you tell me why he didn't considered repulsions?

Hi, I'm looking at the forces exerted onto an anchor point when a n object is dropped but is secured to that anchor point witha steel wire rope lanyard. i can find this but not sure if it is relevant or not to my investigation: Fmax = mg + sqrt(2mg x E x A x fall factor +(mg)2 ) The mass is...

I am working on simulating the movement of small spherical objects under the influence of drag and a number of other forces that, at least for now, don't depend on the object's velocity. Normally I would sum up all these forces, including drag, to ##F_\Sigma## and update the object's speed...

Hi Smart People, I have spent a lot of time on this and have looked in Reed's and Wallker's applied mechanics but can't find a clear explanation. Calculating the force required when pulling up an inclined plane whether horizontally to the plane or at an angle seems pretty straight forward...

First subsystem: $$C_x + F_{DE} \cos(45) = 0$$ $$C_y + F_{DE} \sin(45) + 20= 0$$ $$F_{DE} \sin(45) \times 25 + 20 \times 150= 0$$Second subsystem: $$B_x - C_x = 0$$ $$B_y - C_y - A_y - 20= 0$$ $$-F \times 150 + A_y \times 60 - C_x \times 30 = 0$$Third subsystem: $$-B_x - F_{DE} \cos(45)...

From what I understand, constraint forces do no work because they are perpendicular to the allowed virtual displacements of the system. However, if you consider an unbalanced Atwood machine, in which both masses are accelerating in opposite directions, you'll find that the tension force of the...

Hello everyone! So I have been doing this projectile motion question and do not understand how to do work out which forces act on the archer's left hand in part a)i? I am specifically told to ignore the weight of the bow & arrow. But this is force that only acts downward for the bow & arrow...

please correct me if I'm wrong. is it for the question b, F/l= 0.50 right? does that mean the resultant magnetic force at X is determine by the force at Y and Z? do I need to consider the direction to solve the equation? first step to know the direction of each conductors I use the right hand...

I have solved problem (A). But I couldn't solve problem (B). Here is my attempt:

Hi everyone! So I got a question shown below here and I’m struggling in what the question is trying to say here and what it wants me to give? Here is what I done For when resolving the individual x and y component of forces, my angle has always been measured counter clockwise from the...

I was referring to the conservative and non conservative forces. When i was thinking about it for example when i apply force on an object on the table the object moves a distance and when i remove the force the object does not come back to original position. Can i assume that the force i apply...

Dear experts, How would I find the forces for the truss with both ends pinned? (Fig.1, bottom) I'm trying to determine the forces in all members of some trusses. I've successfully applied the method of sections to a Howe truss (top truss in Fig.1) and I' ve verified it by FEA with MecWay...

The proof of magnetic forces do no work is given in Introduction to Electrodynamics by David J. Griffiths like this My problem is why he has replaced d\mathbf{l} with \mathbf{v}dt? This substitution implies that the charged particle was moving with \mathbf{v} only and no force acted on it...

Just a curious question, is there a limit within the standard model on how many fundamental forces there can be? I have some familiarity with particle physics/QFT(not quite mastery obviously otherwise Id probably be able to answer this myself) and the thought popped in my head when reading about...

Hello all After a lot of support from people like Dr.D, mfig and collinsmark I have finally understood the concept of Centriods and Centre of Mass. I am now trying to understand how a uniformally distributed force and a non uniformally distributed force acts on a shape. If I had an oddly...

Hi. I assume that vector summation of the centrifugal forces acting on the belt, on pulley A and B, equals to zero. Is Centrifugal force on pulley A static or dynamic force? What would, hypothetically, happen if the sum centrifugal forces acting on the belt are not zero? Could some kind of...

For some reason this is something I have really hard time wrapping my head around. Suppose you are sitting on a chair inside a completely closed elevator. The elevator might be moving vertically at a completely constant speed, or it might be completely stationary. It is my understanding that...

Hello all I am trying to work out the forces involved of a moving train around a curve traveling at a constant speed. I have the following:- The image on the left is a cross section of a train traveling around a curve, you can think of the train moving away from you. The image on the right...

I got the equation --> d=mL/[2*(√(2M)^2-m^2)] where M is one of the masses at either end (multiplied by 2 because... there's two of them.) and m is the mass in the middle of the system. Something that a TA told me was that L, the horizontal distance of the system changes. I'm confused by this...

Hello all I was hoping someone could explain why the resultant Fy has a value of +40kN but I get a value of -40kN.

Given: (block a) m = .500kg (block b) m = .200kg that's all... Fg (block a) = (.5)(9.81) = 4.905N = Fn Fg (block b) = (.2)(9.81) = 1.962N i think acceleration might go like... a = (1.962)/(.5 + .2) = 2.8m/s^2 but isn't it supposed to be at equilibrium? So 0m/s^2. How am I supposed to find...

Homework Statement: Solve parametrically the system with g, load cell measurements and know accelerations. Homework Equations: to be found Consider that we know angles tetha(t) of a mass-less link rotating about its centerr O. - so we also have velocities and accelerations - and values of...

I am able to solve this easily using energy conservation, but I'm curious how one would go about solving this using forces and torques?

Summary: Hello; i am trying to work my way thru some motor sizing calculations on a semi-simple example so that i can more easily do it in the future. Could i get some guidance? Hello: I am trying to develop a good system for sizing motors (generally steppers). In the past i just guesstimated...

Hi everyone. I'm the only physics teacher at my school, so I have nobody to bounce ideas off of. I'm having a problem with students getting confused with direction when calculating net force. I teach an introductory physics course. It's the first time the students have ever seen physics and...

Hi all I am trying to get my head around resultant forces. I am happy that if I have a vector diagram with 2 forces I can work out graphically the resultant forces by connecting the head of one of the vectors to the tail of the second vector. The confusion comes in when I have 3 or more...

What forces are exerted by the slot on the slider? You have a normal force since it's inside it, and that's the only force that I can imagine. But then? I think about the pseudo-forces since it's on a rotating reference frame (centrifugal force, Coriolis force, Euler force), but those forces are...

so I can find the centrifugal force but shouldn't the Coriolis force be 0 because the mass is at rest?

I think that there could be friction, but I try to think on forces related to the motion along the Earth, which rotates. Like when you're on a car that turns to the left and you feel pushed to the right. Do the wheels do the same to railway? Would there be Coriolis force? Because that's just...

W and Z bosons, gluons, and photons are all gauge bosons that have been found. Since the graviton can be connnected to atoms and mass in certain ways, I think that CERN may eventually prove the graviton(if real) through smashing atoms that, supposedly, have a graviton orbiting them. Could...

I am trying to solve accelerations of a cart on these different slopes. I don't understand how it is possible without knowing the coefficient of friction, but my teacher says it is (very cryptically I might add). Can anyone help me understand this? Thanks.

Here is my attempt at setting up the equation: I set up the equation to find the acceleration of the box: F-Ffr= m*a after finding the acceleration, I can use the acceleration and plug it in the formula v^2=(v0)^2+2*a(x-x0), which will get me the value of (x-x0)The solution sheet says that F...

Well, I'm having trouble with the free body diagrams. For ##A## we have ##y)## weight, normal force, contact force with ##B##, ##F . sin(36.8°)##. And the acceleration is ##0## because we want to calculate the maximun force before moving. ##\Sigma \vec F = m . a_y## ##\vec N_A + \vec F ...

Alright, to start off: I'm not even sure how this works in the first place. What I do understand is that if they carry current in the opposite direction, using right-hand grip rule, the magnetic field between them will be the same (into the page). Hence using the left-hand rule, I can deduce...

Which could be the first step to find the V(t) ?

Hey y'all Can anyone just tell me every detail about Lorentz forces ? I have a pretty good idea, but i want to surprise everyone in the presentation that i am about to give, so please just tell me whatever detail you know . Every single detail might be helpful . Also , if anyone knows how to...

How mathematically within the confines of mainstream physics would you experts in physics merge Einstein's Field Equations with Quantum Mechanics and Quantum Field Theory? I am looking for a different perspective on this subject usually I get the perspective of "Cranks".