Force Definition and 1000 Threads

  1. D

    Home project: Kilogram Force on wheel bearings

    Hi all. I'm designing a custom spare wheel carrier for my 4wd and currently seeking knowledge on which bearings to use, so I need to work out what force on the bearings will be when it's open (closed will be locked and fully supported!) The example image is simplified for calculation. Close...
  2. C

    Difference in clamping force between bolts and screws

    Hi everyone, I’m trying to figure out the clamping force of a set of screws that thread into a plate. My question is: Would this calculation differ from calculating the clamping force of a bolt with a nut? What would be the difference in how the fasteners/members would react to a tensile...
  3. N

    B Centrifugal force spinning Basketball

    Hi, Looking for Centrifugal force on water droplets on my spinning Basketball at 33 RPM, 45 RPM and 78 RPM
  4. A

    Understanding Driving Force in the m2 Equation: Explained by Experts

    I am having trouble understanding why the second term in the m2 equation, b1(x'2 - x'1), is a negative term. Given that this force is the reason why m2 is moving in the first place, why is it not considered a driving force? I think that I don't have a clear understanding of what driving force means.
  5. N

    The connection between potential energy and force

    Hi, if the force is the derivative of potential energy, does it mean that the force is equal to mg and with a constant gravity, it will be the same at any height? But in real life, F (or mg) would be different on the Earth's surface and 400 km above it (~8 m/s^2). So, this formula is used to...
  6. T

    I What is the relationship between force and potential in particle interactions?

    Suppose I have some interaction potential, u(r), between two repelling particles. We will name them particles 1 and 2. I want to find the force vectors F_12 and F_21. Would I be correct in saying that the x-component of F_12 would be given by -du/dx, y-component -du/dy etc? And to find the...
  7. correction_tape

    Finding the Magnitude of the Force Acting on an Object

    So far, I've only attempted the first number: F = (4kg) [(-4+2t)-0]/t ? Been thinking how to cancel out the time, but I really have no idea how to proceed. Was I supposed to cancel it even? Can someone please help and tell me how you would answer this? (And maybe show a solution as well so I...
  8. Y

    Graphical Impulse calculation from the graph of force verus time

    hello i would like to get some help with this problem. At first it try to calculate the impulse by the area but i found it too difficult Then i try to solve it by the forumla J= F(t-t0), but the problem is that i don't know what F is so i try to solve it like this F10) = 8 F(33) = -13 so EF =...
  9. chane

    The necessary inclined force to rotate an object around an axis

  10. ROOT0X57B

    How to Calculate the Braking Momentum on a Wheel?

    [Mentor Note -- thread moved from the technical forums to the schoolwork forums] I have a hollow-cylinder wheel model, braked with brake pads located at a distance d of the wheel's center axis. The brake pads have a contact area S. They are also forced towards the wheel with a pressure p. The...
  11. alejo ortega

    Resistive force exerted on a sphere (air resistance)

    i don´t understand the question
  12. L

    Force to apply to a loop moving away from a current-carrying wire

    What I have done: (1) ##\Phi(\vec{B})=\int_{S}\vec{B}\cdot d\vec{S}=-\frac{N\mu_0 il}{2\pi}\int_{s=h}^{s=h+l}\frac{ds}{s}=-\frac{\mu_0iNl}{2\pi}\ln(\frac{h+l}{h})## so ##\mathcal{E}=-\frac{d\phi(\vec{B})}{dt}=-\frac{\mu_0iNl^2v}{2\pi h(h+l)}## so...
  13. ols500

    Linking moments with friction force for a sliding block

    Hi so with this question, I am really confused. Even from the start. Like it doesn't tell us where the force is acting on. From top of block, middle of block etc? And I know how to determine the direction of moment for something on a pivot, not in this scenario though. The answer is A. They did...
  14. LCSphysicist

    Understanding the Radial Attraction Force between Two Electric Dipoles

    I am extremelly confused with this question: Basically suppose we have two electric dipoles, parallel to each other, as follows in the figure: I am supposed to show that the force is attractive and radial. But I am not getting how it can be radial (pointing toward each other)! See, the force...
  15. Yossi33

    Need Help with Physics Moment and Force Questions

    hello, i struggle with this kind of questions and i don't understand the way of thinking and how to solve this. in the first picture i don't understand why Moments about point Aare a*F1 because there is the 2 P forces that do moments.? in the second problem i can't understand why there are 3...
  16. A

    B Gravity-like Force: Is Another Force Weaker Than Gravity?

    Is it true that if there was another force similar to gravity (dependent on the stress-energy tensor) then it would have to be weaker than gravity? If so, why?
  17. J

    I Momentum, impact force and Earth

    Suppose two objects, A and B, with large lengths LA and LB, and masses MA and MB, collide at time t0. Both objects before collision are vertical and aligned concentrically, being object B positioned initially at a higher z coordinate than object A. The bottom end of object A is rigidly...
  18. M

    B Angled Rod w Float Attached -- Force of Float

    Hi! A ridged rod is submerged in water at a 45 degree angle toward the bottom of a tank of water. The upper end of the rod is fixed to a pivot point and so, the lower end of the rod is able to move around that pivot point. The lower end of the rod has a float attached to that displaces 50lb...
  19. Pipsqueakalchemist

    Mechanics of machine force analysis with analytical method

    So I was looking at this example problem in my textbook and I don’t understand how they got -168.1 degrees. The part I’m confused with is the first part of the 2nd picture, there’s a coma in the inverse tan, I don’t know what that means.
  20. S

    Calculate the charge on an oil droplet

    The book gives an answer of Q = 3.2 x 10^-19C I get an answer of 6.67 x 10^-19C. Workings below:
  21. E

    Yes! Calculating Friction Coefficient

    Fg = m * g: Fg = 30 * 9.8 = 294 N Fnet = m * a: Fnet = 30 * 1.2 = 36 N Fax = Fnet + Ff: Fax = 36 + 10 = 46 Fa = Fax / cos(angle): Fa = 46 / cos(25) = 50.75 Fay = Fa * sin(angle): Fay = 50.76 * sin(25) = 21.45 Fn = Fg - Fay: Fn = 294 - 21.45 = 272.55 Ff = mu kinetic * Fn, solving for...
  22. A

    I If there is no force being applied can there still be a net force?

    If there is no force being applied can there still be a net force? For example, supposed you apply a force F forward on an object on a frictionless plane, the moment you stop applying the force, the object may still be accelerating towards its final velocity but there is no applied force. So if...
  23. D

    B Creating Artificial Black Hole: Force Requirements

    In a hypothetical deep space experiment in the distant future with appropriate safety precautions in place, how much force/power/energy would be required to create an artificial 1000kg black hole? I haven’t the faintest clue & this isn’t for homework. Where would I even begin looking for an answer?
  24. N

    B Centrifugal Force on Rotating 4" tire / wheel @ 100mph

    Heya PhysicsForums! Remote Control Car toy tires and wheels. a 4" tire/wheel rotates at 8400rpm at 100mph. Am wondering how many "g's" the tire "experiences" at that rpm; I imagine it being hundreds of times (if below is accurate am WAY off with my guess) Using a centrifugal force...
  25. A

    I Water has no shear force but it can be sheared?

    Is it true that water has no shearing force but it can be sheared? If so, would the sides of a glass holding water shear the water?
  26. A

    I What happens to the buoyant force at the surface of the water?

    What happens to the buoyant force at the surface of the water for an object? The buoyant force should be greater than the weight of the object if the object were to float up but once the object floats to the surface, there is no more acceleration upwards which means the buoyant force = weight of...
  27. A

    Trouble Understanding Hinge Axes: Ax ≠ Bx?

    I am confused by the drawing of the door with hinges A and B attached. I do not understand why -Ax = Bx. I would have thought that Ax = Bx
  28. A

    Force of the wall against the ladder is from static friction?

    A ladder is leaning against a frictionless wall and the floor. The force F of the wall against the ladder is what is opposing static friction f at the floor. I don't understand how the force F causes the ladder to slide to the left on the floor unless opposed by friction force f. See picture below.
  29. EmeraldPlatypus

    I Force exerted by an iron core electromagnet on a ferrofluid

    I am trying more generally to find the equation of the fore exerted by an electromagnet. The one that I keep finding is F=((NI)^2 A mu0)/2X^2. N is turn number, I is current, Mu0 is permeability of free space, A is the area of the core and X is the distance from the electromagnet. I take...
  30. Anmol Dubey

    Finding time taken to stop a skater given mass, velocity and force

    I derived the formula for t but don't know how it works Δt = p/F I got p = mv = 60*8 = 480kgms-1 Δt = 480/120N = 4s Is that correct?
  31. J

    Earth's magnetic force on a proton

    Plug in the elementary charge for q, 1000 m/s for v, 50 microtesla for B and 90 degrees for theta and I get about 8e-21 Netwons. But apparently this is wrong, anyone know why? Thank you.
  32. F

    I A paradox for two moving protons?

    Before introducing Special Relativity, a textbook highlights the inconsistency of Maxwell's Electrodynamics and Newtonian Mechanics through the standard discussion about the velocity of light in different frames of reference. A further inconsistency discussed. In some inertial frame of...
  33. A

    I If we throw a ball with initial velocity v0, is there a force?

    If we throw a ball with initial velocity v0, and the ball progresses in a projectile motion, ignoring air resistance, will there be a force in the x direction? If so, what is that force in the x direction's value mathematically? I know there is a force in the y direction due to gravity.
  34. A

    I Does dW/dx = Fx and dW/dy = Fy?

    Since dW = F dot product dr dW/dr = F So dW/dx = Fx and dW/dx = Fy? I am looking at conservative forces where dU/dx = Fx and dU/dy = Fy
  35. A

    I Forces to move on the level versus up an inclined plane

    If on a flat ground, we exert a force F to move forward, then we go to an incline plane of theta degrees. Why wouldn't the force F2 to move up the incline plane with respect to ground be F2*cos(theta) = F --> F2 = F/cos(theta) disregarding the effects of gravity?
  36. Z

    I Why does a body at rest move if Gravity is not a force?

    hello according to GR gravitational force is not a real force rather a space time curvature ok a body in motion follows a sort of invisible rails why doesn't a body at rest remain at rest, then ?
  37. rudransh verma

    What is the minimum force needed to move a block with friction present?

    We know the minimum force to move the body in presence of friction will be ##F>\mu F_N## But it’s not right.
  38. A

    Tension in string pulling two carts

    F - T = m*a 820t - T = m*0.7805t T = 820t - m*0.7805t I am confused what I would use as mass? Mass of cart A, or mass of cart A and tractor?
  39. A

    I Why doesn't the released mass m2 on pulley have higher acceleration?

    Consider the pulley in the attached image to be frictionless. (a) If m2 is released, what will its acceleration be? My question is why wouldn't m2's acceleration be greater if released rather than attached to the string because m2 released is no longer subject to the string's upward force tension?
  40. M

    I Force between Positive and Negative Electrical Charges

    I have in the past been criricised for inappropriate postings that I could have resolved with research so this time I have done the research first. The best solution I have found is from wiki "that causes it to experience a force when placed in an electromagnetic field." What causes the force...
  41. A

    I Mass of Backpack in Moving Elevator

    A backpack is attached to a spring scale which is attached to the ceiling of an elevator. The elevator is moving downwards with an acceleration of 3.8 m/s^2. The scale reads 60 N (Fscale). What is the mass of the backpack? The solution to this problem says that Fscale - w (weight) = Fnet. This...
  42. G

    Force on a particle of a linear charge distribution

    Hello! I am trying to solve this exercise of the electric field, but it comes out changed sign and I don't know why. Statement: On a straight line of length ##L=60\, \textrm{cm}## a charge ##Q=3,0\, \mu \textrm{C}## is uniformly distributed. Calculate the force this linear distribution makes...
  43. B-RY

    Calculating the theoretical force of repulsion between two magnets

    Any help would be much appreciated! Thanks
  44. rudransh verma

    How to Calculate Variable Force on a Particle with Varying Coordinates?

    ##W=-k(y\hat i+ x\hat j)d##. I am not getting the coordinate of particle correctly so that I can find the value of d. Also the force is varying.
  45. P

    How does Newton's 1st Law impact centrifugal force? Does it exist?

    The reading that I have says that centrifugal force (center fleeing) does not exist
  46. kingofjong

    I Maximizing Compound Bow Power: The Role of Longer Limbs Explained

    Hello If a compound bow has longer limbs will it have more power? Longer limbs means more limbs, hence more tension is building when limbs bend. That tension transfers to the bow string. Is this a true statement. I know there are other factors for making a powerful compound bow. Is long limbs...
  47. Spotify

    Net Force of A: Diagram Analysis

    Find the net force of A as shown in the diagram.
  48. A

    I Understanding tension and centripedal force in a puck and weight

    For practice I did the following problem: Solving this problem mechanically was simple enough using the following force diagrams: Then $$F_{net_M} = T - Mg = 0$$ Due to the stationary condition $$T = mg$$ and $$F_{net_m} = T = ma_c$$ $$T = ma_c$$ Because centripedal acceleration is...
  49. rayjbryant

    I Quantifying the magnetic force on a magnet moving through a coil?

    So I'm familiar with the magnet falling through a copper tube demonstration that shows the induced magnetic fields slowing the magnet down. I know that this experiment is also possible with a conducting coil as long as the coil forms a closed circuit. I'm trying to find a way to calculate the...
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