Force Definition and 1000 Threads

As far as I know, there are two causes of the rotational motion of the charged ring. T he first torque is from Lorentz force: $$T=Q\mathbf{R\times ( v} \times \mathbf{B}_{r}) =-\frac{QR^{2}}{2}\frac{dz}{dt}\frac{d\mathbf{B}_{z}}{dz}$$ (where ##\mathbf{B}_{r}...

I have some questions... Firstly I drew the FBD of the said block at an angle theta from the vertical Which force causes the block to lose contact.ie the normal to become zero... Is it because the forces in the horizontal direction surpass some limit value of the net force in the radial...

In my working i have, the attached. My question is Why is the Reaction force not being considered here, My equations are; Frictional force = ## 30\cos 50^0 - 20\cos 40^0 = (19.28 - 15.32)N = 3.96N## The direction will be downwards.

They always talk in boxing and martial arts to stiffen at the moment of impact, but how crucial is this? By way of analogy, how much of a power leakage results from a hammer shaking at point of impact compared to a stiff one? Less concentrated force, surely.

Is this wrong?

I have attempted to solve it as follows: Using the Biot-Savart law, I found the flux density at the centre of the smaller coil due to the bigger coil as: $$\frac{\mu_0 I b^2 N_2}{2(a^2 + b^2)^{1.5}}$$ where a is the distance to the coil (10cm), N2 is the number of loops in the larger coil (50)...

I can get the slope of the line, but then I dont know what the slope is (units or whatever it is) then i get lost from there.

So for this problem I think I am doing something weird with the trig and/or vector components. I calculated the problem like this: First drew a picture, q1 and q2 on the x axis. q3 located equidistant between them but negative .300m in the y direction. First finding magnitude of Electric...

C. There is no net change in force, momentum, or velocity of the sail craft because the fan exerts a forward force on the air; however due to Newton's third law the air exerts an equal and opposite force on the fan. This air then exerts a forward force on the sail which cancels out the rearward...

I am not sure here, even though it is probably simple. If you just hang on the bar and don't move up, you act on the bar with a force equal to your weight. But when you want to do a pull-up, I would intuitively say that you act on the bar with a higher force. But when I think about it I would...

I am stuck on part b) i). I understand that there is no normal force from the ground as the bin is on the point of being lifted off the ground, that is all fine. That leaves R, F and W. I know W is 40g, and I am required to calculate F, therefore it makes most sense to take moments about the...

Hi, How to convert 51065 foot pound per second to Newtons, not Newtons meter per second?

If the engine is constant, then the wheels of the car exerts a constant force on the floor. And F = ma, So the car should be accelerating rather than maintaining the same speed. What is going on here?

it requires less energy to impart acceleration to an object than to the entirety of the universe, This would break the principle of relativity since the amount of energy to move an object should be the same as the amount of energy to move the rest of the universe. This observation implies a...

my answer was A but i dont understand because when the viscous force equals the weight speed becomes constant but why does the viscous force needs to be equal of weight? is it weight = viscous force? or speed = viscous force?

Why is the center of mass acceleration zero? Did I do anything wrong?

my attempt: centre of mass of standing block is at 0.6 and the fallen block is at 0.25 so then change in height = 0.35 and mg = 4000 N so change in gpe = 4000* 0.35 = 1400J but wouldnt we take into account that we only have to apply force till the centre of mass is outside of the block so...

$$F=kx$$ $$k=\frac F x= \frac {50+50~N} {5+5~ cm}= \frac {100~N} {10~cm}= 10~N/{cm}$$ However, the answer is ##5~N/cm##, because the force on the spring is ##50~N##. I am having trouble understanding why the force isn't ##50~N## + ##50~N##. The diagram looks as though the spring is experiencing...

my attempt: no effect

I don't understand why am I getting opposite answers. I get 250N for the lowest point and 750 for the highest point. For the highest point: ##F_{net}=F_{cp}+F_{mg}-F_N## and then ##F_N=ma_{cp}+mg = 50*(25/5)+500=750N## because I've been told that ##F_{cp}## always acts towards the center of the...

$$\mu = 4\pi \times 10^{-7}$$ $$n = \frac{180}{0.135} = 1333.33$$ $$I = 1.85$$ $$L = 22.619$$ $$r = 0.014$$ $$F= \frac{\mu \times 1333.33 \times 1.85^{2} \times 22.619}{2 \pi \times 0.014}$$

Following a conversation with @Tom.G , I’ve come up with the following question, to which we’d both like an answer: Imagine two drilled magnets threaded onto a frictionless upright shaft, set N-N. One fixed down, the other floating above. Now, if I move an iron gate in and out of the gap (the...

Hi, Case 1: Imagine a steady liquid water jet with unit cross sectional area - incompressible and inviscid. density D and uniform velocity V. Operating atmospheric pressure is 0.0 Pa. The jet is in air ( no air resistance ) and hits a stationary flat plate perpendicularly. Applying momentum...

Albeit the simple question, I am a bit confused on whether the correct answer choice is (B) or (C). When the piano is slowing down, shouldn't the force received by the piano be a bit greater than the force received by the man?

Hi, I've problem thinking about this problem isn't the force acting on "nothing"? how can there be any stress, I'm lost!

Can the force of gravity overcome the Planck force? I remember that a long time ago I read that in the universe the Planck force was the maximum force that could be reached. But when Sagittarius A and the black hole at the center of the Andomeda galaxy approach, I have made the calculation that...

I was just wondering if I needed to set up this double integral or not. I've never seen anywhere people setting up double integrals for calculating the work.

Imagine two parallel lines of five magnets each, spaced a few millimeters apart. In the first line, all magnets have their north poles facing one direction. In the second line, each magnet's south pole faces the corresponding north pole of the first line, but the magnets are offset by one along...

I was over on the stack but got asked to move over here. https://physics.stackexchange.com/questions/804903/newtons-3rd-law-force-on-a-rocket I've been at it all day trying to understand what partner forces are and how you can have a change in force with regard to them, or why gravity is...

I will present the case as an exercise because I believe it will be easier to understand that way. I didn't know if I should post it under the mechanics or electromagnetism sections because I am actually trying to link both. Since it feels like a fairly simple problem, I considered the Classical...

Need help in calculating the force required to flange a cylinder outwards around the perimeter by approx. 5mm. Cylinder is either Aluminum or standard Mild Steel. Thank you.

Dark side of the moon! I can understand that Selena Gomez I've been down the darkest alleys Saw the dark side of the moon in Wolf or Transformer movie use that phrase, But this is US Space Force, of all people! US Space Force

Im confused I did 850*9.8*14.7 = 1.2x10^5 Why is it not negative since the force is opposite to the motion?

I did (A) by balancing force on point p (in the figure). I found slope , tanθ = (w^2)x/g. I dont know what to do next. Pls help

Sorry, I guess I should have remembered all of this from my school days, but right now I have forgotten so much that I need some help. I am developing some simple experiments for school children (age ca. 12). This one involving magnets. I am not asking for detailed calculations, that is way...

If we consider ##v=-3t^2## then: $$x=-t^3$$$$a=-6t$$ Using ##t=-x^{1/3}## we have : ##a=-6(-x^{1/3})=6x^{1/3}##. My answer suggust that ##F=Ax^{1/3}## but in options we have ##F=-Ax^{1/3}##. Can someone guide me where my mistake is?

I derived an equation but I have no idea how I can find the mass of the unknown without the normal force in either the x or y direction

My approach is as follows, let ##D## be driving force and ##F## the force resisting motion, then ##D-F = 850 × 0.3## ##D = 250 + 255## ##D = 505## Also, Force parallel to the road is given by, ##F_1 = 8500 \cos 78^0 =1767.24 N## Therefore, the magnitude of Driving force is given by, ##F_1 +...

Is it possible to create something like a circuit powered by the strong nuclear force rather than the electromotive force of a battery? If so, what would be examples of some conductors and resistors that could go in such a circuit?

Hi! My attempt at this solution was: ∫dF = k*q*Q / 2L ∫ (1/r^2) dy and we know that r^2 = D^2 + y^2 based on the diagram. Here is where I start getting confused. I looked at a different physics forum post and the mentor gave this equation: I am mainly confused with the math. How did he end...

A previous question I got correct was: During this time interval, what is the y-component of the average net force on her? It was just 2625, and I thought question 2 would be the same answer but it wasn't. Not sure what to do.

Do the plates of the capacitor exert a force on each other due to opposite electrical charges? Consider a planet capacitor. A simple calculation shows that this force must be very large. If you are not convinced of the magnitude of the force, I will give a simple example.

My first attempt at solving: I divided up the point charges based on the radius away from point A. 1 charge was s*sqrt(3) away, 3 charges were s*sqrt(2) away, and 3 charges were s away from point A. q remained constant. Therefore, my F_total was: F_total = k * [(q^2 /...

The Biot-Savart law gives us the magnetic field created by an electric current. We can calculate the force exerted on a moving charge by this magnetic field using Lorentz's force formula. But my textbook doesn't address the repulsive or attractive force between like or unlike poles...

In the given solution, it states that F_3f(a)=F_2f(a+b) is a "reasonable assumption". However, I don't see how we can just assume that. I can very clearly see that F_i for i=1,2,3 is likely proportional to a and b in some kind of way, but I can not clearly establish a line of reasoning for this...

Hello. I would like to design an experiment where different sled designs are compared. Specifically, I would like to asses how sled design affects the amount of force required to pull a sled over 100 meters. Any suggestions you might have would be greatly appreciated.

Hello. Im studying for an exam and came across this simple unit conversion question but I haven't done something like this in a long time! I understand the conversions of each unit individually but get a bit stuck combining them. This is the question: A force of 100 N is exerted on an object...

How much force will it required to pull a quark out of a proton, and how much for to pull a proton out of a atom ?