Force Definition and 1000 Threads

Hi, Could anyone please give me a little advice. If we look at a disc brake on a vehicle, the disc brake pads apply a friction force on the disk rotor which causes the kinetic energy of the moving vehicle to be turned into heat. Does this heat reduce the reactive force experienced on the disks...

I have a pixel 3xl. The normal camera broke this weekend, but the selfie camera still works. I have an app that I need to scan a qr code once a day for work that only attempts to use the now broken camera. If I could get it to use the selfie camera getting it to line up would be a little...

This was the answer key provided: My questions are the following: if the force required for rotational equilibrium is more than the limiting static friction, then the body will rotate aka slip over the surface. When it slips, the frictional force will be kinetic and not static, right? If I...

First, I think that I need to calculate the capacitance. It is ## C=\epsilon_0*\frac{l*w}{d}-x*\frac{w*\epsilon_0}{d}+\epsilon*\frac{x*w}{d} ##. After that I should calculate the potential energy. It is ##U=\frac{1}{2}*C*V^2 ##. After that I should take its gradient to get the force. So ##\vec F...

Hi - i am confused about the following basic mechanics principles Consider a large cubic mass ( mass M ) on the ground with a small cubic mass ( mass m ) placed on top of it. The surface between the 2 masses is frictionless 1 - if a push (apply a force ) to the large cube does the upper...

Is it possible to create such a strong repulsive force using 2 magnets that it can essentially keep these 2 objects from touching each other? Basically if there are 2 objects coming at very high speeds if both of these objects had a magnet on them that can create such a strong repulsive force...

Hello everyone. Probably this question is trivial, but nevertheless I am confused about Newtons law of motion: $$F=G\frac{m_1m_2}{r^2}$$ Now, some sources say, that F is the force between the two masses m1 and m2. Other sources say, that F is the force that m1 exhibits on m2. But isn’t this a...

I figured out that the pressure is 8.0442x10^7 Pa and I’m not sure how to approach the second half of the question. I’m thinking I use the formula F=PA but I’m realizing it’s not saying that .15m is a diameter or a radius.

Homework Statement:: what force is required to drive a 6ft(1.8 m) 4 inch (100 mm) post 2 ft into the ground? I'm wondering how different soils affect driving ability and where I could find information on soil resistive force. A 20 ton hydraulic tractor mounted cylinder is used to press the...

If exerted a force at 60 cm, should the force F2 be the opposite direction of F1? Thanks!

I calculate in this way as follows and get a correct answer. Howere I am not sure if I am using the right way. F R = (½ MR^2 + MR^2 ) a/R F = 3/2 Ma F - f = Ma f = 3/2 Ma - Ma = Ma/2

A rail gun exerts an electromagnetic force on a projectile. The only moving object is the projectile, so is the point of application of force moving? Update - For others reading this thread, after a re-think on this, for linear motion (as opposed to angular motion), the point of application of...

Let's imagine an ideal scenario where you're lifting your own weight in its entirety. Let's say a woman weighing 100 lbs. Suppose she's doing an idealized handstand and pushup from that position. So she's lifting 100 lbs. Let's say ideally all of the forces are on her arms only. Do these forces...

I have 2 methods, which give 2 different solutions: Let sigma = charge per unit area Let plate 1 be the left plate, plate 2 = right plate. Method 1: Because they are insulating, consider the electric field at 3 regions; region 1 to the left of plate 1, region 2 between the plates, and region 3...

The force per unit area (Pressure) on a part of the sphere is given by F = (E outside + E inside)/2 * Q = 0.5 (kQ/R^2) * (Q/ 4piR^2) = (Q^2/ 32pi^2 e0 R^4). I understand the above line. The solution then says this pressure is exerted on the contact area between the 2 spheres, as given by...

Consider the following situation: You have 1 rectangular block lying on a table, and an identical block is placed above the block on the table. Now, this new block is constantly pushed to the right, right before it topples off. Consider the torque about an axis passing through the rightmost...

Hello there, I was wondering, and i can't seem to really find the answer to my question, i found something that looks like it, but I am not sure if i understand correctly, that why I am turning to PF.com 1) What is the basic formula of the force on a object in flowing water when we assume that...

Hi Guys. I hope everyone is well today. A swing gate of 2300mm x 750mm (LxH) with a uniform mass distribution totaling 64kg. Assuming the force is applied 500mm out from the hinge, how do I calculate the force required to open the gate? If needed, the hinges are hook and eyelet type...

I accelerate charged particle ##A## causing virtual photons to travel to distant charged particle ##B## which feels an electromagnetic force proportional to ##A##'s acceleration (for a classical field description of this effect see https://www.feynmanlectures.caltech.edu/I_28.html Eqn 28.6)...

Here it writes Wby spring= Uinitial - Ufinal. So is it equal to opposite of the change in potential energy ?

So since the block is at the bottom there's no pressure pushing it up. To calculate the mass and force of gravity, I multiplied the density of the block by its height and cross sectional area and got 564 kg. Multiplying this by 9.8 I got the force of gravity of 5527.2 N. Now to find the force...

So this is more of an intuitive question rather than a mathematical one. I present the problem. Assume I have 2 charges of charge +q at a distance r from each other on the z axis. Position of two charges is (0,0,r/2) and (0,0,-r/2). Assume now that I want to calculate the force these two...

Is my solution correct? $$ F(t) = at + b $$$$W=\int_t F(t)dr, ~~~~~~~~~ ~~dr = v(t)dt$$$$W=\int_t F(t)\cdot v(t) dt$$ $$ f = \frac{dp}{dt}$$ therefore $$v(t) = \frac{1}{m}(at^2/2+bt)$$then $$W = \int_t \frac{at+b}{m}\cdot\left(\frac{at^2}{2}+bt\right)dt$$ $$W = \frac{1}{m}\int_t...

I'm reading about the derivation of ampere force law formula, which is $$ F=k_A \iint \frac{i'ds' \times (ids \times \vec{r})}{\vec{r}^2}$$ where K_A is mu_0/4pi. In the article that I read, they have assumed such these paths: And according to ampere's conclusion that he had from observation...

Ok, so we know that if one were inside a donut-shaped spaceship that is rotating around it's axis, that the passengers will experience centripetal force. It seems obvious to say that the ship is rotating relative to the nearby stars and planets. So far, so good. But... what if we removed all...

My first question, so be kind (!) Long time since I was at school, and can only remember the basics of beams and fulcrums. In essence, that a 1kg weight 5mtrs from a fulcrum / pivot needs 5kg at 1mtr to counterbalance. But what about the beam itself? Do the two sides cancel each other out? For...

dP = F dt dE = F dr or if we introduce ds = (dt, dr) (dP, dE) = F ds And both dP and dE are constant in closed system. Some questions: - How does its implies on definition of Force? - Is there some clever geometrical interpretation of Force? - Why P and E seems almost interchengable?

Does a force exerted by a magnet change if we do not change the distance between a magnet and the body, but change the direction of the magnet (tilt)?

I have seen an example of a horizontal beam on a hinge. Beam of length L acted on my gravity MG at center, where the hinge supplies 1/4MG force to the door. Therefore there is a net torque, causing angular acceleration and a net force, causing translation about the center of mass. Maybe it is...

I have attempted this problem by solving for the normal force. (16.73)(9.8)-51.25(sin)(49.1). I tried to work that out but it was incorrect because apparently the vertical force is zero. Could I get an explanation on what that means and where I should start?

I think the answe should be C as shown in the attachment.

Considering an stopped object in a horizontal plane, the frictional force between the object and the plane would be the product of the friction coefficient (static or kinetic if there was movement between the surfaces) by normal. Since the normal in this case would be given by N (vector) = - mg...

A body on a circular orbit in the field of a central force (satellites in gravity field of Earth; a charge in a magnetic field) is subjected to a force which is always perpendicular to its initial velocity v, hence in a time period dt it acquires an additional velocity dv, which is also...

Hi, On a driving force graph ##y = displacement (m)## and ##x = time## where the external force start at t = 0 and the system is in equilibrium at x=0, it's easy to find the driving frequency. $$F = \frac{\omega}{2\pi}, \omega = \frac{2\pi}{T}$$ and we can get ##T## easily with the steady...

first to find the force by gravity, it would be 4 kg * 9.8 m/s = 39.2 N then solve for work using W= F*d*cos(theta) W = 39.2 N * 3 m * cos 28 = 103.83 J My confusion is do I use sine or cosine and what angle do I use, the actual angle of the incline or the angle between the mass and the...

g=9.81 m2g=m1a, a=(m2/m1)g=0.8g F=0.8g x (M+m1+m2)= 0.8g x (21+5+4)= 0.8g x 30= 235.44 N. The answer key however indicate that the answer is 392N. This made me think that the tilt of m2 has something to do with it, but I can't see how much it will make F larger than the above answer.

APPROACH 1 (correct): Height above ground = 3 - (v+u)/2 * t = 3 - 18.263/2 * 0.25 = 0.717 m ----------------------------------------------------- APPROACH 2 (incorrect): Let d be the height from the ground when he is stopped by the cushion. PE loss = Work done against motion by cushion mgh =...

I understand that gravity causes a neutron star larger than about 10 solar masses to collapse into a black hole. I also understand that gravity is the weakest of the four forces. So I find this counterintuitive and I'm puzzled that why is it gravity that causes the collapse and NOT the strong...

Hi, how can I calculate the impact force in case when some object is in uniform circular motion and then suddenly hits the target. For example consider lawn mower's blade hitting stone or drum woodchipper's blade hitting branch. Both blades are already moving at full speed when they hit the...

I split the continuous payment stream into two separate streams: 1. one 10-year payment stream with a rate of 1000 per year 2. one 4-year payment stream with a rate of 1000 pewr year I expressed the present value of this payment stream as: ##\begin{align}...

Could I please ask for help with the following question: A lamina is in the shape of an equilateral triangle ABC, and D, E, F are the midpoints of BC, CA, AB respectively. Forces of magnitude 4N, 8N, 4N, 3N, 3N act along AB, BC, CA, BE, CF respectively, the direction of each force being...

Hello. I am trying to do a basic experiment to demonstrate I⊗β≈ƒ or current cross magnetic field results in a force perpendicular to the plane of the other two. But every time I test this out, it appears I get a force in the same direction as the magnetic field. Here is my experiment: Strong...

At first I tried solving the problemteh following way: Due to symmetry let the rods connected to the green rod have tension forces in magnitde T1 => mg = 2T1cos(a), where a is half the angle formed by the two rods. From tere I got an expression from the longer rods in the force projected by them...

Hi everyone, I have a question that I am struggling and need your help. So I am working on a project which is essentially two syringes, A & B, with different cross-sectional areas, A1 & A2, connected via a tube filled with water. If we assume loss-less system, Pascal's law, the input force...

Hello, I am a Physics undergrad degree graduate who is attempting to do a personal project involving the projectile motion of an American football in a 2D space. I want to take into account the drag force that the ball will experience and also take into account the spin of the football (in the...

Left and right piston produce same vertical force.On both piston, side force is zero,how this is possible if left piston don't has simetrical shape? Why shape of object is irrelevant when fluid has constant/same pressure around object? How can I prove with integration of pressure over left...

The first question concerns reports by people who claim that there is a "force" pulling or pushing their hands when they hold their hands in front of them, close to each other, and parallel to one another, or while slowly moving their hands apart. Obviously there are no significant forces...

My attempt to try and convert book equation to FE manual equation in 3rd pic Fx = QpV1 + P1A1 - QpV2Cosa - P2A2Cosa Fx = P1A1 - P2A2Cosa+ Qp(V2Cosa +V1) P1A1 - P2A2Cos(a) - Fx = -Qp(V2Cosa +V1)

Does anyone know what the minimum speed of a gyro to make it so a force at 0deg will yield a movement at 90deg... or even better, what the angle is wrt speed... see http://www.copters.com/aero/gyro.html for pictures. -thx, rich