rigid

Examples of rigid in the following topics:

• Connected Objects

  • The simplest form of connection is a perfectly rigid connection.
  • Thus it can be said that a perfectly rigid connection makes two objects into one large object.
  • Of course, perfectly rigid connections do not exist in nature.
  • However, many materials are sufficiently rigid, so that using the perfectly rigid approximation is useful for simplicity's sake.
  • Analyze the affect a rigid connection has on the movement of objects

• The Physical Pendulum

  • Gravity acts through the center of mass of the rigid body.
  • For illustration, let us consider a uniform rigid rod, pivoted from a frame as shown (see ).
  • The moment of inertia of the rigid rod about its center is:
  • However, it is not independent of the mass distribution of the rigid body.
  • A rigid rod with uniform mass distribution hangs from a pivot point.

• Hypotonia and Hypertonia

  • Effects of hypertonia include spasticity dystonia (a state of prolonged muscle contractions) and rigidity (a state of muscle stiffness and decreased flexibility).
  • Rigidity has two main forms—"leadpipe" rigidity is stiffness of the muscle, maintained throughout the entire range of movement; "cogwheel" rigidity, typical of Parkinson's disease, is the combination of rigidity with tremors, producing spastic movements.

• The Cell Wall of Bacteria

  • Bacteria are protected by a rigid cell wall composed of peptidoglycans.
  • This rigid structure of peptidoglycan, specific only to prokaryotes, gives the cell shape and surrounds the cytoplasmic membrane.

• Center of Mass and Translational Motion

  • We considered that actual three dimensional rigid bodies move such that all constituent particles had the same motion (i.e., same trajectory, velocity and acceleration).
  • By doing this, we have essentially considered a rigid body as a point particle.
  • This concept of COM, therefore, eliminate the complexities otherwise present in attempting to describe motions of rigid bodies.
  • We describe the translational motion of a rigid body as if it is a point particle with mass m located at COM.

• General Problem-Solving Tricks

  • rigid extended.
  • A force on an extended rigid body is asliding vector.
  • non-rigid extended.
  • A force on a non-rigid body is a bound vector.
  • The body: This is usually sketched in a schematic way depending on the body - particle/extended, rigid/non-rigid - and on what questions are to be answered.

• Center of Mass and Inertia

  • The center of mass for a rigid body can be expressed as a triple integral.
  • In the case of a single rigid body, the center of mass is fixed in relation to the body, and if the body has uniform density, it will be located at the centroid.

• Motion of the Center of Mass

  • We can describe the translational motion of a rigid body as if it is a point particle with the total mass located at the COM—center of mass.
  • We can describe the translational motion of a rigid body as if it is a point particle with the total mass located at the center of mass (COM).
  • Derive the center of mass for the translational motion of a rigid body

• Properties of Macromolecules

  • HDPE is a rigid translucent solid which softens on heating above 100º C, and can be fashioned into various forms including films.
  • Increased crystallinity is associated with an increase in rigidity, tensile strength and opacity (due to light scattering).
  • Amorphous polymers are usually less rigid, weaker and more easily deformed.
  • At 25% to 35% crosslinking a rigid hard rubber product is formed.
  • At temperatures below Tg, elastomers become rigid glassy solids and lose all elasticity.

• Cystoscopy

  • There are two main types of cystoscopy (flexible and rigid), and they differ in the flexibility of the cystoscope.
  • Rigid cystoscopy can be performed under the same conditions, but is generally carried out under general anaesthesia, particularly in male subjects, due to the pain caused by the probe.