S1_L2: Kinetics Flashcards
It is the study of forces acting from the body. These are the driving forces that make the body move, make the body stable, or prevent it from moving.
Kinetics
A state where the body is not in motion, but forces are acting on it.
Statics / Equilibrium
A state where the body is in motion and a driving force keeps it moving.
Dynamics
A hypothetical point at which the body’s weight is equally balanced and mass of the object is concentrated
Center of Gravity (CoG) / Center of Mass (CoM)
Where is the body’s center of gravity located?
An inch anterior to S2 in anatomical position
It is the force that is the gravitational vector
Line of Gravity
TRUE OR FALSE: It is possible for the CoG to be displaced outside of the body depending on the position and movement done.
True
TRUE OR FALSE: Force (gravity) should always start in the center of gravity
True
It is a push or a pull exerted by one object or substance on another
Force
These generate or resist force in the body. Examples of these are
muscles, ligaments, tendons, menisci, joint capsule, and bones.
Internal forces
These are externally applied resistance to the body. Examples are wind, water, dumbbell, other weights, and friction.
External forces
TRUE OR FALSE: Gravity acts on the center of mass of an object and can be considered to be “touching” all objects.
True
Determine the descriptions of the force concepts
- Weight per unit of volume
- Force distributed over a given area
- Product of force and the time over which the force acts
- Mass per unit of volume
A. Impulse
B. Density
C. Specific weight
D. Pressure
- C
- D
- A
- B
Determine the descriptions of the force concepts
- SI Unit: N/m^3
- SI Unit: Pascal (Pa)
- SI Unit: kg/m^3
- SI Unit: Newton-second (N●s)
A. Impulse
B. Density
C. Specific weight
D. Pressure
- C
- D
- B
- A
Determine the descriptions of the force concepts
- Force applied over some distance
- It is the ability to perform work
- Rate of work production
- It is similar to torque
- SI Unit: Watt (W) or Joules per second (J/s)
A. Work
B. Power
C. Energy
- A
- C
- B
- A
- B
TRUE OR FALSE: Pressure is inversely proportional to the surface area of application, while work is directly proportional to force and distance.
True
Determine the corresponding descriptions of the types of parallel force systems
- Can result to fracture injuries in long bones
- Special case of torque where rotation of a segment around its long axis occurs
- Torques applied to a particular point on the object
- Rotational in nature
- Parallel forces applied on unsegmented object
A. Bending Moment
B. Torsional Moment
- B
- B
- A
- B
- A
Determine the corresponding descriptions of the types of linear forces
- Applied parallel to the long axis of object, co-linear and coplanar
- Between two objects, this is proportionate to their masses and inversely proportionate to square of distance between the center of the two objects
- Force that has an action line parallel (flat) / tangential (curved) to contacting surfaces that creates or limits movement between surfaces
- Potentially exists on an object whenever there is a contact force on the object
- Contact forces that are perpendicular to the surfaces that produce them
A. Gravitational Forces
B. Normal Forces
C. Tensile/Distractive Forces
D. Compressive Forces
E. Shear Forces (Fs)
F. Friction Forces (Fr)
- C
- A
- E
- F
- B
Determine the corresponding descriptions of the translatory forces
- Two or more non-colinear forces act on the same segment
- Two or more forces act on the same segment, in the same plane and in the same line
- Two forces of equal magnitude acting in same direction on same plane with counterforce in the middle
- Example is the forces of the ACL & PCL on the knee joint
- Example is the hamstrings and quadriceps on the knee joint
- Converging (intersecting) on same starting point or axis
A. Linear force systems
B. Parallel force systems
C. Concurrent force systems
- C
- A
- B
- C
- C
- C
Determine the corresponding classifications of the ff forces
- Compressive forces
- Tensile/Distractive forces
- Normal forces
- Electrical forces
- Gravitational forces
- Shear forces
A. Non-Contact Forces
B. Contact Forces
- B
- B
- B
- A
- A
- B