Wedge Definition and 280 Threads

A wedge is a triangular shaped tool, and is a portable inclined plane, and one of the six simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place. It functions by converting a force applied to its blunt end into forces perpendicular (normal) to its inclined surfaces. The mechanical advantage of a wedge is given by the ratio of the length of its slope to its width. Although a short wedge with a wide angle may do a job faster, it requires more force than a long wedge with a narrow angle.
The force is applied on a flat, broad surface. This energy is transported to the pointy, sharp end of the wedge, hence the force is transported.
The wedge simply transports energy and collects it to the pointy end, consequently breaking the item. In this way, much pressure is put on a thin area.

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  1. mdcreator

    B What is the Absolute Value of the Normal force on a block on this wedge?

    So i have been solving problems of Newton's Laws of motion and this thing has been quite conflicting for me. I wont complicate my question. I just need one answer. What is the absolute value of normal force on a block of mass M on a wedge? I know it seems a pretty dull question but here me...
  2. N

    Block and wedge problem -- Where am I going wrong?

    This question is from the book Kleppner and Kolenkow Q 3.8: ___________________________________ My attempt is posted here: ___________________________________ The value of a(minimum) that I'm getting is different from the official solution. The official solution is posted here...
  3. PhysicsRock

    I Question regarding the 3-form ##dx^i \wedge dx^j \wedge dx^k##

    Hello everyone, we have recently covered electrodynamics in differential forms. I managed to get familiar with most of the concepts, but one thing came just up where I can't figure out what's going wrong. I tried computing the 3-form ##dx^i \wedge dx^j \wedge dx^k## by hand. However, even after...
  4. A

    Air wedge - why is reflection from top of first slide ignored?

    My textbook derives the condition for bright and dark fringes on an air wedge by assuming that the reflected and refracted rays have a path difference of pi. Hence the conditions for bright and dark fringes end up being the opposite of what is expected. However I did not really understand the...
  5. A

    Air wedge interference pattern after being filled with water

    An air wedge is illuminated with light and an interference pattern is produced. What will happen to the interference pattern when the air wedge is filled with water? The answer given at the back of the book is that the fringe spacing of the interference pattern will increase, however my...
  6. E

    B Normal Force Discrepancy for Wedge Vs. Ramp

    I have seen a few posts on this subject before, but none have really answered my question. For clarity, I will refer to the 1st example as a wedge, and the second as a ramp (although both are of course inclined planes). With both examples that I outline below, we will assume no friction, and a...
  7. Rikudo

    How Does the Wedge's Movement Change with the Disk's Motion Upward?

    So, when the mass reached the peak, its horizontal velocity will be the same as the wedge's. Using conservation of momentum : $$ mu = 2mv$$ $$v = \frac u 2$$ With v is the final velocity for both objects. Now, what we need is the acceleration of the wedge, which we can find by using Newton's...
  8. AspiringPhysicist12

    Block on an accelerating wedge (part c only)

    My solution for part b) (i.e. minimum acceleration) in case it's needed: https://ibb.co/D8CCQMM I'm confused about part c. 1) Since the block will travel up the incline if a > a_max, acos(theta) is up the incline. But based on my attached FBD diagram, acos(theta) should be down the incline...
  9. rudransh verma

    Accelerating wedge with a block at rest on it

    I have drawn a fbd and the logic I think is that at rest the block moves down the wedge but when a force P is applied vertical force becomes zero and the horizontal force ##F_N\sin \beta## = P?
  10. K

    I Rindler Wedge: Timelike or Spacelike? Intuition & Light Cone

    Intuitively, the Rindler wedge is timelike in Minkowski coordinates and an object crossing the horizon enters a spacelike region. This seems at odds with my understanding of the light cone where the 2 regions are reversed. I think this may be related to the signature of the metric but I'm not...
  11. G

    I Wedge product of a 2-form with a 1-form

    Let ##\omega## be 2-form and ##\tau## 1-form on ##R^3## If X,Y,Z are vector fields on a manifold,find a formula for ##(\omega\bigwedge\tau)(X,Y,Z)## in terms of the values of ##\omega## and ##\tau ## on the vector fields X,Y,Z. I have known how to deal with only one vector field.But there are...
  12. rudransh verma

    To move a block up to the top of the wedge

    I think on top of the wedge the KE of both the wedge and block will be same but this fact doesn't take me anywhere. The base length of the wedge is not given. Maybe that would have helped.
  13. D

    Magnitude of force acting on wedge and block

    Clearly if ##F = 0## and ##\tan\theta > \mu_s##, then using the above equations for ##f_s## and ##n##, we get ##f_s > \mu_s n## so the block will slip. However, it seems that as long as the force ##F## is directed to the right with a certain minimum magnitude, namely ##\frac{\tan\theta -...
  14. A

    I Conservation of KE, wedge striking ball

    So assume we have a wedge traveling at a constant V horizontally, that is braced so it CANNOT move vertically. Ignore air and friction. See picture. It hits a stationary tennis ball and due to the angle, there is a net force on the ball as shown. The energy should come from the kinetic...
  15. K

    Virtual displacement for a block sliding down a wedge

    A block slides on a frictionless wedge which rests on a smooth horizontal plane. There are two constraints in this system. One that the wedge can only move horizontally and another that the block must remain in contact with the wedge. We want to find the virtual displacements for the two block...
  16. Pipsqueakalchemist

    Engineering Dynamics help: Block on a wedge on an incline (frictionless surfaces)

    So I’m having trouble with relative motion with moving inclines and I literally can’t find any help online and my prof does a lot of these problems. This is one of my homework problems, can anyone help me with it please.
  17. M

    Oblique shock waves: how to find the wedge angle for trailing shock?

    Hi, I have a question regarding oblique shockwaves. Question: How can we determine what the wedge angle is for the shockwave in a situation? Context: This problem here shows an oblique shock wave on the trailing edge of the body and it simply states that the wedge angle is 6 degrees. Why is...
  18. T

    Calculating the Force Required for a Moving Wedge and Block System

    The entire mass of the wedge is ##(M+m)## therefore ##F=(M+m)a##. The forces acting on the small mass are its downward weight ##mg## and the normal force with the contact of the wedge therefore I got that ##N=mg\cos\theta##. Similarly the horizontal component is ##N=ma\sin\theta## therefore...
  19. J

    MHB Calculate volume of non parallel wedge

    Hi, just wondering how I would calculate the volume of this wedge? see photo attached
  20. Hamiltonian

    Block on a wedge connected to pulleys

    if the tiny block moves downward by an amount x, the wedge should also move forward by the same amount x as they are connected by the same string whose length has to remain constant, (by differentiating it wrt time we get speed) hence I concluded that v1 = v2, but my book says otherwise what is...
  21. Leo Liu

    Normal force acting on a block on an accelerating wedge

    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...
  22. Leo Liu

    A block on an accelerating wedge

    For question b, the official solution sets up a non-inertial coordinate on the block and writes out the following two equations: $$\begin{cases} \begin{align*} f\cos(\theta)+N\sin(\theta)-mg=0 \qquad \hat\jmath \\ N\cos(\theta)+f\sin(\theta)=ma \qquad\quad\;\;\, \hat\imath \end{align*}...
  23. Alabaster1327

    A 2.00 kg rim with a radius of 20.0 cm is sitting on an 8.00 kg wedge

    https://www.physicsforums.com/attachments/264405
  24. F

    Wedge Tensile Grip Design - UTM Testing Machine

    Hello to all. I am new at PF. I am very happy to be here now that I know you. I am at the middle of a UTM (universal tensile machine) design. My machine is going to be a simple testing machine in which I only intent to measure the ultimate tensile strenght. That been said, I want to be as clear...
  25. Like Tony Stark

    Equations of motion of a block on a spinning wedge

    I think that the only force acting on the wall is the normal force caused by Coriolis force, so it can be calculated this way: ##N=m2\dot r \dot \theta## But ##\dot r## is not constant, so how can I calculate it? Then, I can't calculate the acceleration either since I don't have the value of...
  26. Yalanhar

    Acceleration of a moving wedge with a falling block

    When the box travels a ## X## distance, the wedge travels ## \frac{X}{2}##. So ##a = 2A## Using the wedge as a non inertial frame: I didn't use (4). Using (2) on (3) and then on (1) I got: ##2mA=mgsin\alpha +mAcos\alpha + \frac{-mgcos\alpha sin\alpha +mAsin^2\alpha +MA}{2cos\beta -...
  27. G

    Mechanical Advantage of a Compound Wedge

    Length of wedge/width of wedge = mechanical advantage
  28. P

    Why is the wedge force positive?

    As per (b) in the above image, or easily solved with t=rFsin(theta), the perpendicular force is 260N. When inputting that value into the equation for torque, the value for torque is 520Nm, as per t=2.00*300*sin60. Because the wedge prevents the door from moving, the torque on/at the doorknob...
  29. newbie12321

    B Do Wedge Constraint Relations Affect Velocities Parallel to the Contact Surface?

    There’s a rigid rod pushing on a wedge. Velocity of the rod is v, which is vertically downwards, and the wedge is sliding to the right as a result with a velocity u. There is zero friction on the surface of the wedge and the surface of the rod in contact with the wedge. According to wedge...
  30. Like Tony Stark

    Acceleration acting on a block lying on a wedge (non-inertial frame)

    I have some difficulties trying to understand non-inertial frames. I have problems to notice the acceleration in these cases, from an inertial reference frame and from non inertial refrence frame. Consider the first case, if I'm on the wedge, I see that the block doesn't move so there's no...
  31. Prabs3257

    Why is my answer for the rotating wedge problem not matching?

    I tried making the fbd of both blocks the block on the incline will have mgsin30 friction force, tension and centrepetal force's cos component similarly second block will have mg tension and friction where normal will be centrepetal force after solving my ans is not matching
  32. A185

    Dynamics: A wedge, a mass, and two pulleys

    Problem Statement: In the arrangement shown in the figure, a block of mass m=2kg lies on the wedge of mass M=8kg.Find the initial acceleration of the wedge. Assume pulleys and thread massless and surfaces smooth. Relevant Equations: FBDs
  33. Kaushik

    A small mass on a wedge having a stationary circular track

    A small mass of ##m## starts sliding down a wedge which is having a stationary circular track on it. If ##M = 2m## and friction exists between the wedge and the horizontal surface. Draw the Frictional force vs Theta graph. How to draw the graph? Please HELP
  34. VVS2000

    I Air Wedge Experiment: Conditions for Bigger Scale?

    Are there any specific condintions for air to act as a screen? I just did my air wedge experiment yesterday and was wondering if we were to do it on a bigger scale, how would we do it?
  35. Shivam

    A smooth massless wedge is pushed by a horizontal Force P....

    Answers- 1,3,4 My attempt, the wedge being massless, there shoul not be any force acting on as it will then have infinite acceleration, so by that i really can't think of how force is applied on pully.
  36. baldbrain

    Find the impulse exerted on the wedge by the ground during impact

    Now, the net vertical impulse on the wedge should be zero. It's quite obvious from the figure that the ground will also exert an impulse of ##J cos 30°## on the wedge. But they've given the answer as ##J sin 30°##. They're wrong, right?
  37. J

    MHB Symmetric/Alternating k-linear functions, Wedge Product

    I am working through Tu's "An Introduction to Manifolds" and am trying to get an understanding of things with some simple examples. The definitions usually seem simple and understandable, but I want to make sure I can use them for an actual function. I've worked a few problems below that my...
  38. Math Amateur

    I Wedge Product and Determinants .... Tu, Proposition 3.27 ....

    In Loring W. Tu's book: "An Introduction to Manifolds" (Second Edition) ... Proposition 3.27 reads as follows: The above proposition gives the wedge product of k linear functions as a determinant ...Walschap in his book: "Multivariable Calculus and Differential Geometry" gives the definition of...
  39. Math Amateur

    I Anticommutativity of Wedge Product .... Tu, Proposition 3.21

    I am reading Loring W.Tu's book: "An Introduction to Manifolds" (Second Edition) ... I need help in order to fully understand Tu's Proposition 3.21 ... ... Proposition 3.21 reads as follows: In the above proof by Tu we read the following: " ... ... ... ##= \sum_{ \sigma_{ k + l } } (...
  40. Math Amateur

    I The Wedge Product .... Tu, Section 3.7

    I am reading Loring W.Tu's book: "An Introduction to Manifolds" (Second Edition) ... I need help in order to fully understand Tu's section on the wedge product (Section 3.7 ... ) ... ... The start of Section 3.7 reads as follows: In the above text from Tu we read the following: " ... ... for...
  41. M

    I Parameterize a circle based on the contact angle with a wedge

    Hi PF! Given a 2D plane, the following is a parameterization of a circular arc with contact angle ##\alpha## to the x-axis: $$\left\langle \frac{\sin s}{\sin\alpha},\frac{\cos s - \cos\alpha}{\sin\alpha} \right\rangle : s \in [-\alpha,\alpha]$$ However, I am trying to parameterize a circle...
  42. M

    Conceptual Question: Block on a wedge on a frictionless surface

    Homework Statement This is more of a conceptual question, but say a block was set on top of an inclined plane, which was set on top of a frictionless level surface. Would the inclined plane move? Why or why not Homework Equations None The Attempt at a Solution My thought...
  43. M

    A Exploring Wedge Product of 0-Form and l-Form

    Hello, we defined the wedge-product as follows Alt is the Alternator and the argument of Alt is the Tensor poduct of one k-form and a l-form (in this order w and eta). Suppose we have the wedge product of a 0-form (a smooth function) and a l-form , so the following may result: $$\frac{1}{l!}...
  44. L

    Find min/max accel. for block to stay on wedge (static fric)

    This HW problem due date has already passed. I had no problem with part a, but struggled thinking about parts b and c. I saw the solutions for parts b and c, but still don't exactly get it. I'll state the questions below, and tell you my way of interpreting the solution now. Could you tell me...
  45. navneet9431

    Three blocks and a spring on an inclined plane....

    Homework Statement See question number 1. Homework Equations Work Energy Theorem, work done by all the forces=change in K.E. The Attempt at a Solution I tried solving this question this way, please help me calculate the Work Done by spring here?? I will be thankful for any help!
  46. A

    Quick clamp wedge/friction lock calculation

    I am currently working on designing a linear brake/lock for a completely different purpose but it will be based on the same principle as in a quick clamp shown below. Before building a prototype I do want to make some rough calculations to check dimensions, angles etc. etc. However, I am for...
  47. M

    I Conformal Mapping Wedge to Plate

    Hi PF! Does anyone know the conformal map that takes a wedge of some interior angle ##\alpha## into a half plane? I'm not talking about the potential flow, just the mapping for the shape. Thanks!
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