Force Definition and 1000 Threads

HI τ= r ˆr x - ##k / r ^ 2## ˆr= 0 right? since ˆr x ˆr is zero What about L?

Surely a tough one, I am doing it from the basics. This is the diagram i tried to draw showing the Force and current I The Length L is the tangent to the circle. The Force F is pointing upwards at ##90 Deg## to the ##\vec B## and also perpendicular to ##\vec L##. I am considering a small...

hi guys, i can't understand why they calculate F yin this way, the part of floor that is the vertical proyection has less water than the floor in the left so i tought Fy would be less, please can someone explain this concept to me?

So my doubt is at the beginning of the problems hey are saying that the ball obeys stokes law and on the latter part of the question they are saying that no buoyant force is acting then how does the velocity of the ball change in the end? Also what is the use of specifying 'the ball never...

First i will use a equation resulted in considering a spring as a continuum limit of massive mass: ω = √(KL/ρ)*kn ρ is the linear density ρ ω = √(KL/ρ)*kn X = A*cos(kn*x)*cos(ω*t) ξ = A (first consequence) X = ξ*cos(kn*x)*cos(ω*t) ∂y/∂x need to be zero in x=L (for strain be zero) kn*L =...

Given a force of tension with a string attached to the front of the box, do we take the force as acting with an angle to the centre of the mass of phi or theta? Explain please?

My question is: given a rigid body which interacts with a surface, what's the direction of the normal force? Because, as the word says, it has to be normal to the surface. But when treating problems of a vertical rod which is slightly pushed and forms an angle ##\theta## with the surface, some...

So I already have a solution available to this problem and the link for the solution is: I have understood everything in the video except the part where they are equating the force dF=GM/r²*dm According to my reasoning the inner part of the sphere (the part below the dm element we have taken)...

There is a trampoline drawn here and a graph of the spring force vs height. I don't see why the spring force is decreasing at a decreasing rate with respect to height above trampoline. F= kx = k * h/sin(theta), letting theta be between the horizontal and the spring.

Hello, I am a creative scifi writer and i only have basic quantum physics knowledge, if someone could answer my question please. I was wondering some type of weapon that uses weak force, therefore it would promote distorcions at weaf force field causing interaction with atoms My question is, if...

When figuring out the capillary pressure on a liquid in a tube of a certain cross-section, the typical approach is to consider the Young-Laplace pressure and the curvature etc. I was looking through some of my old notes and I had an equation for the capillary force: fc = γ cosθ dS/dx where γ...

$$ \frac{62 - .4mg + (.2) (m_{net} g)}{m} = a(t)$$ And, then I put ths into $$S=\frac{1}{2} at^2$$ But, my answer is not quite coming with what's in the options? So, my main confusions are, SHould the bottom most surface exert a force on the top most block, also where am I making mistakes...

At a total loss here

I am seeking some professional help regarding a recent single man lift I purchased. My question is regarding tipping force calculations. I will try to explain all of the pertenent details as best as possible. The lift I bought weighs approximately 600 lbs. It moves around on caster wheels but...

##\vec \tau = \vec \mu \times \vec B -eq1## ## F = I \vec l \times \vec B -eq2 ## The forces i have indicated The magnetic moment is coming out of the page. I am only attempting only the part (a) as of now a. The force calculations are F1 = 1.4*0.22*1.5 = 0.462 +X direction F2 = 1.4*0.22*1.5...

This is my first post in this great community. English is not my native language, so i am sorry for any mistakes. I need to build a pill crusher using a pneumatic cylinder with 30mm stroke (effective travel). i have e metal container with 25mm base diameter where i have to make powder from 6-8...

First and foremost, thank you so much for your help! I'm new to Physics Forums, and this is my first post. I thought I understood the problem, but as I moved on to the subsequent parts of it became apparent that I was missing something. I set up my ##F = ma## equation as below, and solved that...

I am studying the theory of force on a current carrying conductor in a uniform magnetic field, the Force is ## F=ILB##. I am slightly confused here let us say the conductor is placed in the uniform magnetic field ##B##, then if the current is passing through the conductor then that current would...

If a free body diagram is constructed for 1kg, one might be inclined to draw an arrow downwards with only the weight of 10N. However, the downward, non-net, force on 1 kg is (1+5) x 9.8. Why is this the case? It seems very counterintuitive.

We have a wedge whose surface is ##\theta## from the horizontal surface. After a block is placed on its frictionless slant surface, the wedge starts to accelerate due to a force F. What is the normal force acting upon the block? I have been trying to solve it but I got no clue. Could someone...

Because this problem is easier to understand with a picture, I'll just copy paste the original problem. There is no question about the validity of the solution. My question is about the statement in the solution "Consider the instant when the mass is moving vertically upward. In this instant the...

I feel that force is also function of time.

Hello, I was glazing through what I would consider an advanced physics textbook and I saw this image. It is a schematic picture of an alpha-particle in a field of an atom. Now, can someone get me started on what (and why and how) is going on in it? Especially with the fraction with pi.

The displacement of the end of a spring varies as , the block on the spring is subject to a viscous force proportional to the velocity. Spring stiffness k. (a)Find the displacement of the block: (b)When γ -> 0 First of all, i have a doubt i we could start saying the component of the force is...

I was just reading through these lecture notes regarding the stresses in solenoids, and came across the following regarding a current-carrying ring orthogonal to a uniform magnetic field, I wondered if this is a piece of terminology that I haven't come across? To me the total radial force is...

The magnetic energy of a current carrying spring, with ##N## turns, length ##x## and cross sectional area ##A##, is $$E_m = \frac{\mu_0 N^2 I^2 A}{2x}$$The (negated) spatial derivative of this yields a quantity with dimensions of force,$$F = - \frac{dE_m}{dx} = \frac{\mu_0 N^2 I^2 A}{2x^2}$$How...

Bit of a random question... capacitors can be a bit weird, in that if we connect one up to a source of EMF and do positive external work to separate the plates of the capacitor, the energy of the capacitor decreases (and instead the work you do plus the decrease in capacitor energy goes into the...

The problem is how to construct the right diagram of forces actually Unfortunately, the Fo*cos acting on the ball will not carry the g/l of the solution -mg*sin(´p) + (-bv) + (Fo*cos(wt)*cos(p)) = mx'' Fo*cos(wt) = mx'' + mg*x/l + bv

when we have 0 acceleration(constant speed) like a car traveling at a constant speed, ƒnet=ma ƒnet=(mobject+mfriction).(aobject+afriction) let m object be 1500 kg. m friction be 10 kg a object be 0 a friction be 20m/s^2 so when we calculate fnet=-20*1600=-32 000 Newtons. which means wall applies...

When the lamina rotates about A, FA must act on B (because it is the farthest away) perpendicular to AB (so that all of FA contributes to rotation). Same argument is valid for rotation of lamina about B as well. Having noted that, I tried two approaches: Approach 1- If I assume that the...

I remember, a few weeks ago, when looking for homework problems I could help with, seeing one as described in the title. I couldn't think of an easy solution and was busy at the time so i made a mental note to think about it later. I finally got around to doing that yesterday, and brushed up on...

Why I think gravity *is* the only force doing work on the rider: 1) The only forces acting on the rider are gravity and the normal force. Broken down into their component vectors, we have: -> The component of the force of gravity moving parallel to the rider's direction of motion -> The normal...

If you take a bar magnet and place a wire with current a short distance from the end, Lorentz's law can be used to accurately predict the location and magnitude of the resulting forces. The same is true if you use a large volume uniform magnetic field to create an induced field in a bar ferrite...

Hi All, I am working on this linkage mechanism. Please see the attachment for images. There are 3 pivot points. Two of which are connected to the ground. The" Inside Leg 1" is telescopic to "Leg 2" and has a 120 LB compression gas spring connected at mount points as shown in the image. The leg...

Hello all- I am trying to design a simple cell phone holder that will be printed using a 3D printer. For this phone holder I would like the base to be the minimum length possible to avoid the thing tipping over backwards. I drew a simplified slope and base which represents the phone on the...

I don't know if this is a dumb question, but I just can't seem to wrap my head around it. I can imagine and feel when I'm pressing against a wall, that there's a force. Especially when the wall is not moving, I can continually increase the strength of my push and feel a greater resistance from...

I´m currently studying Newtons 2nd law and I don't get how can force only depend on mass and acceleration and not on velocity.. I mean, if I punch something with my fist going at constant velocity ( acceleration=0) it stills has a force right?

I am new to this forum, and this is my first post. Please bear with me if my query has any inaccuracies. In the attached figure, a coil is wrapped around the central arm of a flat H-shaped thin metallic plate (such as iron). DC current flows through the coil and magnetizes the arm. At the...

My understanding of emf Let us consider 2 parallel plates with charges (opp. but equal in magnitude) stored on it. When we connect both the plates from the outer side, the electrons from the lower potential (i.e., negatively charged plate) moves to the higher potential (positively charged plate)...

Hi, Which force does govern the neutron elastic scattering and capture reactions? It seems to me it is the strong nuclear force, but I am not sure about that.Thanks.

What is the direction of the frictional forces especially when there are 2 forces acting on an object? (see attached Image)

a) the EMF of ℰ induced on The Wire, as a function of the speed 𝑣of the wire you can find it. b) flow induced in the wire𝑖, 𝐶, 𝐵, and are denominated in 𝑙 𝑎 (𝑎= the acceleration of the wire). c) find the magnetic force acting on the wire in𝐶,𝐵, 𝑙 and𝑎. d) 𝑎 acceleration, 𝑚, 𝑔, 𝑙, and are...

We feel that Earth pull as to the ground but is Earth accelaritng up "in some way" so gravity is also inertial force?? I read that we still don't understand what is gravity...

I have attempted solving this problem several times on an long since finished online quiz. However no answer I gave seemed to be correct despite what I could reasonably understand regarding the effect of seatbelts and their effect on reducing force by extending the distance of deceleration...

The problem is symmetric around the z axis, thus the force must be in the z direction only. I tried dividing both rings into differential elements, then integrating through the upper ring to get the z component of the total force on the upper ring due to a differential element of the lower ring...

A chain with length L and mass density σ kg/m is held in the position shown in Fig. 5.28, with one end attached to a support. Assume that only a negligible length of the chain starts out below the support. The chain is released. Find the force that the support applies to the chain, as a function...

This is diverted from the Classical Physics forum. My first approach was this: the force ##\vec{F}## can be written in polar coordinates as ##\vec{F} = F \hat{\theta}##. It follows that ##F_{\theta} = ma_{\theta} \implies F = m(2\dot{r}\dot{\theta} + r\ddot{\theta})##. This result also agrees...

Hello, I am looking for some help. I have completed the question below. I will show my answers. My answer: I believe this to be correct. If it is not would appreciate someone letting me know so i can correct. Now i am attempting this question: Could anyone help, or point me in the...

Astrophysicist Scott Manley determined the energy required to destroy a planet (2.25 x 1032 joules). Is the energy required to destroy 3 planets simply a case of multiplying his result by three? If not, how much energy would it take to destroy 3 planets? This scenario relates to Incredible Hulks...