Force Definition and 1000 Threads

  1. archaic

    Exploring the Magnetic Force and Torque on a Current-Carrying Wire

    a) On QP, the force is zero. On PR, the force is directed inside the plane, and its magnitude is ##0.8IB##. On QR, the force is direction out of the plane, and its magnitude is ##1IB\sin(\arctan(0.8/0.6))=0.8IB##. b) ##0.8IB-0.8IB=0##. d) It will rotate outside of the page. c) I know that the...
  2. mastermechanic

    Rigid body kinetics -- force on ankle joint

    PROBLEM Here from the conservation of angular momentum I found angular velocity just before impact, $$ H_1 = 0 $$ $$ H_2 = I_0\omega + mV_0d $$ $$ H_2 = 66\omega + 76.(1.2).(0.87)$$ $$ H_1 = H_2 $$ $$ \omega = 1.202 rad/s $$ But I couldn't solve it to find joint force. Thanks in advance,
  3. J

    Understanding Tension in a Physics Scenario

    Confused on how to find tension in rope (this would be the force acting on mass 2 that is causing work). Fnet wouldn't be 0 since the speed isn't constant and no acceleration is given. I'm sure I'm suppose to use the masses in an equation somehow, but I'm not sure how. It makes sense that the...
  4. C

    Determine the force in the bar CB

    I solved this with two methods as you can see down below in the picture. Which is the correct way? I remember I learned in class you could use both ways but why am I getting different results?
  5. L

    Man on an Elevator -- Force Diagrams

    I really need help figuring out where to start. I believe that every graph has a normal force pushing up on the person as well ag gravitational force pushing down on them. Where I am getting confused at is how the velocity plays into the scenario and if an acceleration of 9.8 m/s^2 downwards is...
  6. D

    Engineering Finding the reaction force using the unit load method

    I just wrote down what I think and have no idea of it...please help me with this question
  7. Olivia Lam

    What is the reaction force between the ring and the hoop?

    a.)N cos θ=mg N sin θ=mrw^2 sin θ cos θ=g/rw^2 b.) My question is reaction force =N ? or =F=mg tanθ ? If it is N then N=mg cosθ =mg^2/r w^2 or N=mg/cosθ =mrw^2 ? Thank you
  8. SwatiAnshu

    Calculation of Eddy Current Brake Force with a twist

    All the equations I have seen have a component that is unknown. Also, if possible do let me know if there is a software I can use to model or analyze data related to eddy currents
  9. A

    Coriolis Force and Centrifugal Force

    Hello! So for a) I have done the following m = 400t = 400000 kg v = 300 km/h = 83,3 m/s ##\alpha## = 50 (degrees) Now this is the formula for the Coriollis effect $$ F = 2 \cdot m (v × \omega) $$ So in a book I found in the library regarding physics I've found a similar example that used...
  10. S

    What is the maximum frictional force?

    In the attachment I am supposed to calculate the maximum frictional force of a block on a 35 degree angle incline (that is the point at which the force acting opposite frictional force is highest) I make it out to be sin(35)*120N = 69N but the book says 675N and it gives it as...
  11. W

    [Statics] Determining the normal force at an internal point of a member

    For this problem (see image), I get the correct answer for the normal force at point E if I: 1) divide the frame into members AB and CB, 2) solve for the x and y components of the reaction force at point B, 3) make a free body diagram with the cut at point E forming member EB and setting the sum...
  12. C

    Is the Braking Force of a Truck Really 0.8?

    Hi guys I'm a truck driver. Not sure if I'm posting in the right place so i apologise. Iv'e been on a course today about trucks. The course leader was talking about forces. A trucks force forwards can be 0.8. Is this true?
  13. greg_rack

    Best straightforward method to calculate the direction of the Lorentz force

    Hi guys, I'm being introduced to magnetism, and the direction of the Lorentz force is quite confusing since it's involving a vector product. Which method would you recommend me in order to easily deduce the direction?
  14. Amrator

    Relativity: Force and a Collision

    I don't know if I did this correctly. ##\int Fdx = \int dE## ##F \Delta x = \Delta E## ##Fx = Mc^2 - (mc^2 + mc^2)## ##M = \frac{Fx + 2mc^2}{c^2}## ##M## is the mass of the resulting particle. ##2mc^2## is the total energy before the collision. The issue is I'm assuming that the resulting...
  15. TonyCross

    Calculating Theoretical Reaction Force of Ball Traveling in Semi-Circle

    Summary:: Theoretical reaction force due to ball traveling in a semi-circle circum Hi, Can anyone please help me with the following question: Setup... 1 x length of pipe bent 180 degrees with an inner diameter of 22mm, it's radius is 2mtrs, the mass of this object is 100kg. Total length of...
  16. Andrei0408

    Expression of the force derived from this potential

    I just don't know what equations I should use, or what exactly I need to do. I just need some guidelines, thank you!
  17. N

    What is the Relationship Between Force and Weight?

    So here's what I've tried: force from part (a) / weight = 499.649N / 15kg = 33.310 force from part (b) / weight = 10.511N / 15kg = 0.701 Apparently this wasn't correct. What am I doing wrong? I feel like I'm missing the obvious.
  18. SamRoss

    Magnetic attraction / repulsion from the Lorentz force

    I'm trying to understand how the Lorentz force can explain why magnets attract and repel. The explanations that I have found have mostly involved the magnets moving in a way that decreases the forces between them ( ) but I have not been able to find any intuitive explanation involving the...
  19. P

    I Finding the Velocity of an object due to an imparted force

    Hello folks, I was wondering how I could calculate/find the velocity of an object from an imparted force given its mass. My force is 26 MN, the object is 10 metric tons, or 10kKg, what will the objects velocity be if this force was applied to it rapidly, e.g. like a jab/punch. My goal is to...
  20. L

    Engineering Cantilever and encastré beams: bending moment and shear force

    I have to discuss the Bending moment and shear forces in cantilever and encastré beams. Does anybody know of good websites showing that is simple to understand showing. All i can find is how to calculate and bending moments and shear force digrams which don't really understand. Can...
  21. L

    Engineering Bending motion and shear force

    A cantilever beam 2 meter in length, 5KN act at point (A) of the beam. There is point x it looks like half way along the beam. how do i workout the distance of point X so work out the magnidues of Ra and Rb so i can go onto working out bending motion and shear force?ruff idea i had 1) Ra x 2...
  22. F

    I Special Relativity & Non-Instantaneous Force Equations

    In classical mechanics, the gravitational force is described by the equation: F = Gm1m2/r^2 What would this equation - or other similar equations - look like in special relativity? This equation cannot be correct because it implies that the force acts instantaneously.
  23. Mr_Allod

    Understanding the Force on a Magnetic Dipole in Different Orientations

    Hi there, I approached this problem by making use of the fact that a dipole can be modeled as a small current loop with the magnetic field ##\vec B_1 = \mu_0 \frac {m_1}{4\pi r^2} (2\cos \theta \hat r + \sin \theta \hat \theta)## which is the far-field approximation for a regular circular...
  24. P

    Finding Force and Energy from an indentation into a volume

    Hello folks, a recent theoretical discussion with a materials engineer has left my head spinning, this sort of thing is beyond me but I am curious if any of the clever folks on here could solve my problem. I want to find the Force and Energy applied by my Indenter within the following...
  25. K

    Understanding of Wave swing physics

    Yeah, as I said, i have no idea why we can assume beta to be the same for any position at given alpha.
  26. B

    Is friction really always related to the normal force?

    What I know is that the force of friction and the normal force are the components of a contact force. So force of friction is related to the contact force. Friction is also related to the normal force by equation ##F_t= μ\cdot N##. In this case (because the block is not moving) N=0 and...
  27. andyonassis

    Gyroscope (Coriolis Torque and Force)

    I know that to prove the total coriolis torque from the coriolis torque on a point mass is to express dm as a function of ##d\theta## and integrate from 0 to ##2\pi## and then the x component disappears due to orthogonality of sine and cosine. But i am stuck at other parts.
  28. Caw

    Centripetal force problem involving a washing machine

    Summary:: Just want to know if I'm on the right track with this question. Hi, so this is what I have for my assignment: A washing machines drum is rotating rapidly about a vertical axis (a so-called toploader). A wet sock is stuck on the inside, halfway up the drum, and the drum begins to slow...
  29. archaic

    Cylinder rolling due to magnetic force

    Hello! The magnetic force is to the right. ##I_c## is the moment of inertia of the cylinder. For the net force on the centre of mass, I have the frictional and magnetic forces ##F=F_B-f##. I know that ##F_B## is ##IdB##. I also know that ##rf=I_c\alpha=I_c\frac ar##, so that...
  30. shk

    Force and motion -- A water drop on the windscreen of a car

    Hi Please help me with part C. I have answered the question and have attached it for you to see.
  31. K

    Selection of a compression spring

    Summary:: What does I need to consider in order to get the right spring? Hello. I need a compression spring that require 10 lbs of force in order to be compressed 1cm. The springs outer diameter (De) has to be 1cm. The spring will be made out of piano wire. Which values of specification does...
  32. Hamiltonian

    Doubt related to buoyant force and fluid thrust force

    (this problem is slightly modified from the original problem.) There is a contact force(friction and normal force) between the wedge and the walls of the container and there is a fluid thrust acting on the side of the wedge in contact with the fluid( this force is normal to the slanted surface...
  33. Ntip

    Force on conductors during a short circuit fault

    If I have two parallel bars serving as a DC bus with a capacitor across the output and there is a short fault event, I know the peak current is limited by V/X. The instantaneous current would be a function of the time RLC time constant. How do I relate this to the force on the conductors due to...
  34. SamRoss

    I How is the weak force related to a change in velocity?

    Hi everyone, The four fundamental forces are gravity (I understand that G.R. does not look upon gravity as a force but I'm not worried about that here), the Lorentz force, the weak force, and the strong force. I'm familiar with the inverse square law for gravitation and the Lorentz force...
  35. S

    Why is the Force on the Wire Directed from Stronger to Weaker Field?

    I understand how the weaker and stronger field occurs but I don't understand why the force on the wire is directed from stronger to weaker field. I mean why not from weaker to stronger? I also want to ask about Newton's 3rd law in this case. Newton's 3rd law states that for every action there...
  36. B

    Net force acting on a ping-pong ball

    w= 0.50N, Fn= 7.8N, angle= 29 Fnet= Fn*fd* costheta = 7.8*0.50*cos(29 = 3.41 is my answer correct
  37. rbmartel

    I Which area should I use to calculate the force on a submerged surface?

    Let's say we have a tank filled with water only half way up. I want to calculate the force being applied by the liquid on one of the walls, that's F = P.A. For the area (A), should I consider the area of the entire wall (H.L), or only the area of the wall that's in contact with the liquid...
  38. LuisBabboni

    I Why is the weak force a force?

    Hi! I could understand gravitational force as a force that move mass. I could understand electromagnetic force as a force that moves chaerged particles. I even could understand strong force as a force that atrack protons I could not understand the moment of what weak force changes. The moment...
  39. T

    Quadratic Drag Force: Solving Differently

    But the answers to these two questions confuses me. For the first question the answer goes like: $$m\ddot y = -mkv^2-mg$$ $$\therefore \ddot y = v\frac{dv}{dy}$$ $$\therefore v\frac{dv}{dy}= -kv^2-g$$ but for the answer to the second question we have: $$m\dot v = mg - cv^2.$$ Both questions...
  40. M

    B Mass of Hanging Rope: Calculate Easily

    Hi, I have a question about a hanging rope - how do you find it's mass? I've been searching a long time, stumbled across some advanced calculus involving catenary functions and equations, but couldn't quite figure it out.
  41. J

    Direction of the Coriolis force

    How can I determine direction of Coriolis force for these cases?1)Ship travel at 45th north parallel to the east (course 90°)2)Ship travel at north hemisphere at course 45°3)Ship travel at equator at east (course 90°) My attempt: 1) Coriolis force is point up,vertical to the Earth surface 2)I...
  42. S

    Determining net force and acceleration

    Hi All, Please see attached photo of the question. It is asking for net force and acceleration. Taking the forces acting upwards and downwards on the parachutist as vectors: for A the net force would be 800-300=500; B would be 0 and C; would that be 800-1500=-700? And if so would that imply...
  43. Feodalherren

    Torque to force conversion (from a motor)

    So this is a silly problem that I ran into at work which made me realize that I have all but forgotten Newton's laws of motion after years of working with just hardware and software. I am in the middle of programming a robot for an industrial application and I realized that I have no clue how...
  44. G

    Force in the legs of a hexagonal table

    We know that the net force on the table must be zero $$\sum F_i = F$$ We know that the components of the torque with respect to the origin is also 0. $$\sum \tau_x = 0$$ $$\sum \tau_y = 0$$ $$\sum \tau_z = 0$$ But the problem becomes insufficiently constrained that there are only 4 equations...
  45. B

    Finding the resultant force using a vector polygon diagram

    Hi I made an attempt at this problem but have got the wrong answer The correct answer is actually resultant force = 21.767 N at 61.34 degrees (or 151.34 degrees bearing), but I don't know how they got that? Any help would be appreciated! Thanks
  46. R

    Electromotive Force, Batteries, Resistors, and Potential Differences

    I have attached a small excerpt from my digital book where they start talking about emf. I am very confused. Let me explain what is confusing to me so that you can clear up what's bothering me. They start of by saying that an emf device pumps charges by maintaining a potential difference...
  47. N

    Analyzing Velocity and Force of a Chain in Motion

    My solution: For the horizontal portion of the chain: let at any instant the length of chain inside the tube is x, and at that instant the chain in the tube is having a velocity v. Then, at any instant: ##F = \frac{\mathrm{d} p}{\mathrm{d} t}## ##p##= mass of the chain in the tube at the...
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