What is Applied force: Definition and 127 Discussions

In lithic analysis, a subdivision of archaeology, a bulb of applied force (also known as a bulb of percussion or simply bulb of force) is a defining characteristic of a lithic flake. Bulb of applied force was first correctly described by Sir John Evans, the cofounder of prehistoric archeology. However, bulb of percussion was coined scientifically by W.J. Sollas. When a flake is detached from its parent core, a portion of the Hertzian cone of force caused by the detachment blow is detached with it, leaving a distinctive bulb on the flake and a corresponding flake scar on the core. In the case of a unidirectional core, the bulb of applied force is produced by an initiated crack formed at the point of contact, which begins producing the Hertzian cone. The outward pressure increases causing the crack to curve away from the core and the bulb formation. The bulb of applied force forms below the striking platform as a slight bulge. If the flake is completely crushed the bulb will not be visible. Bulbs of applied force may be distinctive, moderate, or diffuse, depending upon the force of the blow used to detach the flake, and upon the type of material used as a fabricator. The bulb of applied force can indicate the mass or density of the tool used in the application of the force. The bulb may also be an indication of the angle of the force. This information is helpful to archaeologists in understanding and recreating the process of flintknapping. Generally, the harder the material used as a fabricator, the more distinctive the bulb of applied force. Soft hammer percussion has a low diffuse bulb while hard hammer percussion usually leaves a more distinct and noticeable bulb of applied force. Pressure flake also allowed for diffuse bulbs. The bulb of percussion of a flake or blade is convex and the core has a corresponding concave bulb. The concave bulb on the core is known as the negative bulb of percussion. Bulbs of applied force are not usually present if the flake has been struck off naturally. This allows archaeologists to identify and distinguish natural breakage from human artistry. The three main bulb types are flat or nondescript, normal, and pronounced. A flat or nondescript bulb is poorly defined and does not rise up on the ventral surface. A normal bulb on the ventral side has average height and well-defined. A pronounced bulb rises up on ventral side and is very large.When explained visually, the bulb of percussion is visible on the ventral face as opposed to the dorsal face (where it is smoother) and considered to be on the "inside" of the parent core. The bulb of percussion is the primary feature that identifies the ventral surface of a flake or blade artifact. Locating its position reveals which is the proximal end of an artifact. Along the proximal end there may be the formation of ripple marks. These ripple marks allow for the direction traveled by the applied force through the lithic when it was detached. Typically, the striking of the flake is produced by knapping (or flintknapping), a process in which requires the user to chip away material from high-silica stones like "flint" in a carefully controlled manner with special tools to produce sharp projectile points or tools. A common characteristic that is associated with the bulb of applied force is a bulbar scar. This scar is from a small chip or flake on the bulb. This is known as an eraillure flake scar. It is produced during the initial impact of flake removal. Occasionally, there is more than one contact point on a striking platform which creates a series of superimposed waves. The eraillure flake is a chip removed through contact of a dominant force wave that creates the conchoidal flake and inferior waves. Bulb of applied force is not produced by bipolar technology or wedging initiation.

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  1. tellmesomething

    B Spring mechanism confusion

    Consider a spring in its natural length. I start pulling the string and the force i apply increase from 0 to 5, while this happens theres a restoring force wanting to be back in its original position(intermolecular force) and i am able to stretch the string until this spring force or restoring...
  2. K

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  3. paulimerci

    For which case would the applied force be greater?

    If F is applied at an angle above the horizontal, it decreases the normal force and vice versa. So in case A, net force along X = F applied cos theta - friction since the object is moving with constant velocity, a = 0 and so the above equation becomes F applied cos theta = friction Now along...
  4. mopit_011

    B Equivalence of Frictional and Applied Force

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  5. E

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  6. kara123

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    -i had begun by finding the normal force =147 N -then found the force of friction=99.96 N -found the work of friction=-799.68 J after that I am unsure of where to go since I don't have a force applied
  7. vibha_ganji

    B What Happens When The Applied Force Equals the Static Friction Force?

    In my teacher’s notes, it said that when the applied force on an object equals the maximum static frictional force, the object begins to move at constant velocity. My question is if both the applied force and the frictional force cancel as they are equal in magnitude, what force accelerates the...
  8. H

    The magnitudes of the applied force F and the frictional force f of a wheel

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  9. GreenOlive

    Change in acceleration with change of angle of applied force

    Let ##μ_k## = 0.5 ##F_a## = 10 Newtons ##\theta## is the angel of the Applied force. How will the acceleration of the block change if the angle of the applied force is increase by ##5^o##? Write Increase, Decrease or Stay the same. Recently we were discussing a question similar to this in...
  10. I

    Direction of friction in yo-yo where applied force is at top

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  11. M

    Force between two different metals?

    Hi everyone... I work in a rolling mill that produces train rail tracks. But I'm experiencing some problems. The guards I use keep breaking. So here is the scinario. The rail we make is 40kg per meter. With a total length of around 65m. When it goes thru the mill pressure is applied to it in...
  12. A

    Newton's 3rd Law Dynamics Problem

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  13. J

    Applied force compared friction force at constant velocity

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  14. N

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  15. R

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  16. JustynSC

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  17. StarWarsNerd

    B Calculating Linear and Angular Quantities from Applied Force

    In the image above, a centroid with radius 1 is depicted. F1 is pointing directly at point A (which is the center of the circle), and F2 is pointing directly at point B. The radius for finding the torque would be the perpendicular between the center of the object and the force vector, so r1...
  18. T

    Derivation of Applied Force in a Grade 12 Force Question

    Homework Statement When an applied force elevated at angle θ is used to drag mass m along a surface with μ as the coefficient of friction, the mass accelerates horizontally with some value, a. Derive the cleanest and most simplified formula for the applied force, Fapplied, that will give the...
  19. szc

    Single Direction Applied Force Locking Mechanism

    Having trouble researching/discovering any locking mechanisms that engage with force in a linear direction and then allow the engagement to be released with force in the same applied direction. I don't know if it has been done, any help/findings would be greatly appreciated. The only technology...
  20. Zack K

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  21. N

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  22. diazdaiz

    Kinetic friction and applied force

    I think this question is not important and rarely noticed, but I'm still curious XD kinetic coefficient of friction is used when the applied force of static friction coefficient is less than than the force that we give, or less than or equal to the force that we give? sry for my bad english
  23. blueray101

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  24. B

    What forces causes the top book to accelerate horizontally?

    Homework Statement A small textbook is resting on a larger textbook on a horizontal desktop. You apply a horizontal force to the bottom book and both books accelerate together. The top book does not slip on the lower book. What forces causes the top book to accelerate horizontally? Homework...
  25. I

    What are the forces acting on a child pulling a wagon up an inclined hill?

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  26. J

    Calculating stress and strains for beam of applied force

    Homework Statement If I consider a force, which is applied to both ends of a rectangular beam to its cross section with dimensions w (width) and h (height) and I know the length of the beam is l and the force is parallel, how can I calculate the stress? Also, what if the force were parallel to...
  27. B

    What are the components of an applied force?

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  28. B

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  29. B

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  30. alphaj

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    Homework Statement Muscle can be torn apart by a force of 100,000 N applied across an area of 1 m2. A 10 cm2 muscle therefore will be torn by a force of 100 N. If a student of average size were being lowered into a black hole of 1 solar mass, at about what distance from the hole's center will...
  31. O

    Friction force has different effect than Applied Force?

    Hi, I'm wondering what's going on when a friction force of a surface is applied to a moving block as the block slows down to zero and it, the friction force, is the only horizontal force applied. Does the friction force continue at a constant value until the last moment and just drop to 0N or...
  32. C

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    Homework Statement Three boxes are in contact with each other on a frictionless horizontal surface as shown. The masses of the boxes are m1 = 10 kg, m2 = 20 kg, and m3 = 30 kg. A horizontal force F = 90 N is applied to m1. Calculate: a. the acceleration of the three boxes. b. the net force on...
  33. S

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  34. B

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  35. G

    Can you find the applied force with just the initial and final velocties?

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  36. S

    Frictional force with appiled force at an angle

    Homework Statement An applied force of 30N acts on a 8kg box at an angle of 40 degrees above the horizontal. What is the acceleration of the block if =0.1 and μk = 0.05? What is the acceleration of the block without any friction? Homework Equations Equation 1 F k = μ k F N...
  37. M

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  38. M

    What type of of force is applied force? Conservative ,Nonconservative

    In a closed loop when we apply an applied force on an object the object starts at point A and stops at point A. Since the displacement is 0, Work done by the applied force on the object is = F x s x cosθ...
  39. S

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  40. S

    Need some help finding applied force & coefficient of static friction

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  41. G

    Acceleration After Applied Force is Stopped?

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  42. W

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  43. J

    Sliding box question- finding applied force with friction

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  44. G

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  45. M

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  46. C

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  47. J

    Finding Applied Force from Coefficient of Friciton and mass

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  48. W

    Help: Applied Force Formula(?)

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  49. M

    Max. Applied force on outside wall of spinning drum

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  50. S

    Static & Kinetic Friction + An Applied Force on an Inclined Ramp

    Homework Statement A box with a mass of 22 kg is at rest on a ramp inclined at 45 degrees to the horizontal. The coefficients of friction between the box and the ramp are μs = 0.78 and μk = 0.65 a) Determine magnitude of the largest force that can be applied upward, parallel to the ramp...
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