mcat math kinetics and dynamics

  1. force
    • pushing or pulling on objects
    • the forces can exist between those not touching
  2. gravity
    attractive force that is felt by all forms of matter
  3. all objects exert gravitational forces on each other
  4. two types of force
    • gravity
    • friction
  5. friction force
    • type of force that opposes the movement of objects
    • it may cause an object to go slow or stationary
  6. 2 types of friction
    • static
    • kinetic
  7. static friction
    • between a stationary object and the surface upon which it rests
    • the coefficient is dependent on 2 materials
  8. normal force
    component of the force between two objects in contact that is perp to the plane of contact between the object and surface upon which it rests
  9. kinetic friction
    • exists between a sliding object and the surface over which the object slides
    • anytime two objects slide across each other, kinetic friction will be present
  10. 2 differences between static and kinetic friction equations
    • KF has an equal sign meaning it will have a constant value given any combo of KF and NF
    • two equations have a diff coefficient, Us is bigger than Uk, so SF will be greater and will stick before they move
  11. mass
    measure of the body's inertia (amount of matter in an object)
  12. Newton's 3 Laws
    • a body at rest or in motion at a constant velocity will continue until a force acts upon it (law of inertia)
    • no acceleration will occur when the sum of the forces results in the cancellation of those forces
  13. linear motion
    objects velocity and accel are along the line of motion
  14. air resistance opposes the motion of the object, so an object falling will experience drag force as the velocity increases
    the drag force will=the mag to the weight of the object and will fall with constant velocity (terminal velocity)
  15. uniform circular motion
    instant velocity vector is always tangent to the circular path, meaning, the object tends to break out of its pathway and move in a linear direction but is kept from doing this due to centripetal force. once CF is no longer acting on the object, the object will exit the pathway and assume a tangible path from the circle
  16. force and acceleration are vectors and accel is always the same direction as the net force
  17. dynamics
    study of forces and torque
  18. translational equilibrium (first condition of equilibrium)
    exists when only the vector sum of all of the forces acting on an object is zero
  19. if no accel, there is no net force, but just because the force is 0 does not mean the velocity is
  20. rotational motion
    • forces are applied against an object i such a way as to cause the object to rotate around a fixed pivot point (fulcrum)
    • is generated by torque not force itself
  21. moment of force
    appliced force at some distance from the fulcrum that generates torque
  22. rotational equilibrium (second condition of equilibrium)
    vector of sum of all torques acting on an object is 0
  23. the mcat takes rotational equil to mean the object is not rotating at all
  24. KE objects that have mass move with some speed
    • faster they move, the more KE they have
    • it is relation to speed not velocity, so
  25. PE
    energy associated with a given objects position in space or other qualities of the system
  26. gravitational potential energy
    depends on the objects in space with respect to some level known as ground
  27. the first law of thermodynamics
    energy is neither created not destroyed
  28. total mechanical energy accounts for potential and kinetic only
    • unless friction force is present, the energy can be given off in heat and dissapate from a system
    • if no nonconservative forces are present, thats when KE and PE are constant
  29. conservative forces
    those that are path independent and that do not dissipate energy
  30. work energy theorem
    • expression of the relationship between work an E
    • and can be applied to changes in other forms of E
  31. simple machines
    • provide a mechanical advantage
    • wheel/axle,pulley,wedge,and screw
  32. in mechanical advantage displacement is pathway independent, the actual distance traveled from initial to final doesnt matter if one assumes all forces are conservative. so less force over a great distance to accomplish same change, accomplishes the same amount of work
  33. mechanical advantages of an inclined plane
    reduction of necessary force at the cost of increased distance to achieve a given value of work or energy transference
  34. pulleys allow heavy objects to be lifted without much force
  35. theoretically pulley is massless and frictionless under theoretical conditions, the work put into a system comes out of the system
  36. considering simple machines, load and effort are both forces to consider to determine output force and input force
Card Set
mcat math kinetics and dynamics
mcat kinetic and dynamics math