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  Rosie Roza created a new knowledge: Force (en)

  Force (en)

  In physics, a force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate. Force can also be de...  moreIn physics, a force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a push or a pull. A force has both magnitude and direction, making it a vector quantity. It is measured in the SI unit of newtons and represented by the symbol F.
  The original form of Newton's second law states that the net force acting upon an object is equal to the rate at which its momentum changes with time. If the mass of the object is constant, this law implies that the acceleration of an object is directly proportional to the net force acting on the object, is in the direction of the net force, and is inversely proportional to the mass of the object.
  Concepts related to force include: thrust, which increases the velocity of an object; drag, which decreases the velocity of an object; and torque, which produces changes in rotational speed of an object. In an extended body, each part usually applies forces on the adjacent parts; the distribution of such forces through the body is the internal mechanical stress. Such internal mechanical stresses cause no acceleration of that body as the forces balance one another. Pressure, the distribution of many small forces applied over an area of a body, is a simple type of stress that if unbalanced can cause the body to accelerate. Stress usually causes deformation of solid materials, or flow in fluids....    less

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• 
  Ananth Narayan has added a new cover photo.

  

  • 1 hour ago

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• 
  Rosie Roza created a new knowledge: Torque (en)

  Torque (en)

  Torque, moment, or moment of force is rotational force. Just as a linear force is a push or a pull, a torque can be thought of as a twist to an object. In three dimensions, the torque is a pseudovector; for point particles, it is given by the cross produc...  moreTorque, moment, or moment of force is rotational force. Just as a linear force is a push or a pull, a torque can be thought of as a twist to an object. In three dimensions, the torque is a pseudovector; for point particles, it is given by the cross product of the position vector (distance vector) and the force vector.
  The symbol for torque is typically
  
  
  
  τ
  
  
  {\displaystyle \tau }
  , the lowercase Greek letter tau. When it is called moment of force, it is commonly denoted by M.
  The magnitude of torque of a rigid body depends on three quantities: the force applied, the lever arm vector connecting the origin to the point of force application, and the angle between the force and lever arm vectors. In symbols:
  
  
  
  
  
  τ
  
  =
  
  r
  
  ×
  
  F
  
  
  
  
  
  {\displaystyle {\boldsymbol {\tau }}=\mathbf {r} \times \mathbf {F} \,\!}
  
  
  
  
  τ
  =
  ‖
  
  r
  
  ‖
  
  ‖
  
  F
  
  ‖
  sin
  ⁡
  θ
  
  
  
  
  {\displaystyle \tau =\|\mathbf {r} \|\,\|\mathbf {F} \|\sin \theta \,\!}
  where
  
  
  
  
  
  τ
  
  
  
  {\displaystyle {\boldsymbol {\tau }}}
  is the torque vector and
  
  
  
  τ
  
  
  {\displaystyle \tau }
  is the magnitude of the torque,
  r is the position vector (a vector from the origin of the coordinate system defined to the point where the force is applied)
  F is the force vector,
  × denotes the cross product, which is defined as magnitudes of the respective vectors times
  
  
  
  sin
  ⁡
  θ
  
  
  {\displaystyle \sin \theta }
  .
  
  
  
  
  θ
  
  
  {\displaystyle \theta }
  is the angle between the force vector and the lever arm vector.The SI unit for torque is N⋅m. For more on the units of torque, see Units.  less

  • 1 hour ago

  • Drazen Vorih likes this.
• 
  Ananth Narayan pin onto Rubiks Cube:

  

  Rubik's | Cubes, Puzzles, How-to-Guides & More | Rubik's Official Website

  A cube for relaxing and improving condition reflex, making you to think and makes brilliant. I tried and found lot's of change in me.

  • 1 hour ago

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• 
  Rosie Roza created a new knowledge: Rotational speed (en)

  Rotational speed (en)

  Rotational speed (or speed of revolution) of an object rotating around an axis is the number of turns of the object divided by time, specified as revolutions per minute (rpm), cycles per second (cps), radians per second (rad/s), etc..The symbol for rotati...  moreRotational speed (or speed of revolution) of an object rotating around an axis is the number of turns of the object divided by time, specified as revolutions per minute (rpm), cycles per second (cps), radians per second (rad/s), etc..The symbol for rotational speed is
  
  
  
  
  ω
  
  cyc
  
  
  
  
  {\displaystyle \omega _{\text{cyc}}}
  (the Greek lowercase letter "omega").
  Tangential speed v, rotational speed
  
  
  
  
  ω
  
  cyc
  
  
  
  
  {\displaystyle \omega _{\text{cyc}}}
  , and radial distance r, are related by the following equation:
  
  
  
  
  v
  =
  2
  π
  r
  
  ω
  
  cyc
  
  
  
  
  {\displaystyle v=2\pi r\omega _{\text{cyc}}}
  
  
  
  
  v
  =
  r
  
  ω
  
  rad
  
  
  
  
  {\displaystyle v=r\omega _{\text{rad}}}
  An algebraic rearrangement of this equation allows us to solve for rotational speed:
  
  
  
  
  
  ω
  
  cyc
  
  
  =
  v
  
  /
  
  2
  π
  r
  
  
  {\displaystyle \omega _{\text{cyc}}=v/2\pi r}
  
  
  
  
  
  ω
  
  rad
  
  
  =
  v
  
  /
  
  r
  
  
  {\displaystyle \omega _{\text{rad}}=v/r}
  Thus, the tangential speed will be directly proportional to r when all parts of a system simultaneously have the same ω, as for a wheel, disk, or rigid wand. It is important to note that the direct proportionality of v to r is not valid for the planets, because the planets have different rotational speeds (ω).
  Rotational speed can measure, for example, how fast a motor is running. Rotational speed and angular speed are sometimes used as synonyms, but typically they are measured with a different unit. Angular speed, however, tells the change in angle per time unit, which is measured in radians per second in the SI system. Since there are 2π radians per cycle, or 360 degrees per cycle, we can convert angular speed to rotational speed by
  
  
  
  
  
  ω
  
  cyc
  
  
  =
  
  ω
  
  rad
  
  
  
  /
  
  2
  π
  
  
  
  {\displaystyle \omega _{\text{cyc}}=\omega _{\text{rad}}/2\pi \,}
  and
  
  
  
  
  
  ω
  
  cyc
  
  
  =
  
  ω
  
  deg
  
  
  
  /
  
  360
  
  
  
  {\displaystyle \omega _{\text{cyc}}=\omega _{\text{deg}}/360\,}
  where
  
  
  
  
  
  ω
  
  cyc
  
  
  
  
  
  {\displaystyle \omega _{\text{cyc}}\,}
  is rotational speed in cycles per second
  
  
  
  
  
  ω
  
  rad
  
  
  
  
  
  {\displaystyle \omega _{\text{rad}}\,}
  is angular speed in radians per second
  
  
  
  
  
  ω
  
  deg
  
  
  
  
  
  {\displaystyle \omega _{\text{deg}}\,}
  is angular speed in degrees per secondFor example, a stepper motor might turn exactly one complete revolution each second.
  Its angular speed is 360 degrees per second (360°/s), or 2π radians per second (2π rad/s), while the rotational speed is 60 rpm.
  Rotational speed is not to be confused with tangential speed, despite some relation between the two concepts. Imagine a rotating merry-go-round. No matter how close or far you stand from the axis of rotation, your rotational speed will remain constant. However, your tangential speed does not remain constant. If you stand two meters from the axis of rotation, your tangential speed will be double the amount if you were standing only one meter from the axis of rotation.  less

  • 1 hour ago

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• 
  Rosie Roza created a new knowledge: Rotation (en)

  Rotation (en)

  A rotation is a circular movement of an object around a center (or point) of rotation. A three-dimensional object can always be rotated around an infinite number of imaginary lines called rotation axes ( AK-seez). If the axis passes through the body's cen...  moreA rotation is a circular movement of an object around a center (or point) of rotation. A three-dimensional object can always be rotated around an infinite number of imaginary lines called rotation axes ( AK-seez). If the axis passes through the body's center of mass, the body is said to rotate upon itself, or spin. A rotation about an external point, e.g. the Earth about the Sun, is called a revolution or orbital revolution, typically when it is produced by gravity. The axis is called a pole....    

  • 2 hours ago

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• 
  Drazen Vorih → Sheet Metal Design:

  AVT 206 A&P - P2 - Developing Sheet Metal Flats - The Math Behin

  This video is an explanation of the math on the FAA Airframe test. You can learn to bend metal without doing this math - but this video is about doing the ma...

  • #CATIA
  • #SolidWorks
  • #3D modeling
  • #Autodesk Inventor
  • #sheet metal

  • 2 hours ago

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  Sergio Lanna
  

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  Sergio Lanna uploaded a new part Pen Holder @ PARTcloud.net

  

  Pen Holder

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  昊维 何 uploaded a new part QJR-D型减速器 @ PARTcloud.net

  

  QJR-D型减速器

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• 
  Sergio Lanna
  

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  Drazen Vorih → PARTcloud 3D Modeling World Championship 2018:
  

  • #Challenge
  • #3D modeling
  • #championship
  • #render

  • 4 hours ago

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• 
  Drazen Vorih uploaded a new part Santa - Pen holder @ PARTcloud.net

  

  Santa - Pen holder

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  Ananth Narayan → PARTcloud 3D Modeling World Championship 2018:
  

  • #Challenge
  • #3D modeling
  • #championship
  • #render

  • 5 hours ago

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• 
  Ananth Narayan uploaded a new part Mechanical Pen Stand @ PARTcloud.net

  

  Mechanical Pen Stand

  • 6 hours ago

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