PHYSICS (CETS)

• Physics


  properties and interrelationships of matter and energy, excluding chemical and biological changes.
• Coordinate System


  a mathematical method used to represent the position of points
• Quantity


  a physical property of a object that can be quantified by measurements
• Variables


  a symbol that represents a quantity

  • used in formulas
• Unit


  standard amount of a physical quantity

  • how it is measured
• Statics


  objects at rest and at equilibirum
• Dynamics


  study of why stuff move

  • started with Isaac Newton and his three laws
  • explains why things move the way they do using and relating the force to accelertion
• Kinematics


  study of how stuff move

  • started with Galileo
  • describes how things move and how to predict their movements, but does not explain the movements
• Kinematic Formula when displacement is not given

  Vf = Vi + at
• Kinematic formula when acceleration is not given

  d = (Vi + Vf / 2) t
• Kinematic formula when final velocity is not given

  d = Vit + 1/2at^2
• Kinematic formula when time is not given

  Vf^2 = Vi^2 +2ad
• Distance(d)


  scalar quantity that measures the interval between two locations measured along the actual path connecting them
• Displacements (>d)


  a vector quantity that measures the interval between two locations measured along the shortest path connecting them
• Speed (v)


  scalar quantity that measures the rate of motions

  • rate of change of position of an object over time

  A) speed = distance / time

  
• Acceleration (>a)


  rate of change of velocity over time

  A) a = Vf- Vi / t

  
• Newton's Law of Universal Gravitation


  any two bodies in the universe attract each other with a force that is directly proportionate to the product of the masses of two bodies and inversely proportional to the square of the distance between them.

  A) F(g) = G m1 + m2 / r^2

  
• Gravitational Constant (G)

  6.67 x 10^-11 N m^2/kg^2
• Projectile


  an object or body thrown with an initial velocity and whose motion is influenced by the pull of gravity
• Trajectory


  the path of a projectile that follows through space
• Gravitational Free Fall


  motion of an object ventically downward with initial velocity of zero
• Projectile Motion


  motion of a body (the projectile) projected into the air with constant acceleration

  • gravity only affects vertical motion, not horizontal motion
• Three Laws of Motion

  founded by Isaac Newton

  Newton's First Law of Motion - Law of Inertia

  Newton's Second Law of Motion - Law of Acceleration

  Newton's Third Law of Motion - Law of Interaction
• Law of Inertia


  states that a body will remain in its state of rest or in uniform motion along a straight line unless acted upon by an oustsde force
• Inertia


  the capacity of an objects to resist charges in motion

  • mass is directly proportional to inertia
• • force required for an object to move and stop
  • only objects in constant velocity and 0 velocity does not require force
• Law of Acceleration


  a net force acting on a body produces an acceleration which is the direction of the force
• Net Force


  sum of all forces acting on an object

  • A is directly proportional to F and inversely proportional to M
• Force Formula

  F = ma
• Weight

  measure of gravitational force

  • in Newton (N) units
  • Formula: w = mg
• Mass


  measure of inertia

  • measured in kilograms (kg)
• N = 1kg * 1m/s^2
• Law of Interaction


  for every force, there is an equal and opposite force

  • these two forces are equal in magnitude and is opposite in direction
• Momentum(p)


  product of the mass of an object and its velocity
• Linear Momentum Formula

  p = mv
• Impulse (Ft)


  product of the force and in time during which the force acts on the body

  • when objects collide, the momentum is conserved
  • Formula: (p1 + p2)initial = (p1+=2) final
• Impulse-Momentum Theory

  Ft = change in p

  • concentration of linear momentum
  • Formula: (mv)final - (mv)initial
• Collision


  when an object in motion comes into contact with another object

  • linear momentum is conserved between the two objects

  Formula: (p1+p2)initial = (p1+p2)final
• Elastic Collision


  objects involve remain separate

  • total kinetic energy and momentum is conserved
• Inelastic Collision


  the objects collide into one mass

  • total momentum is conserved but not total kinetic energy
  • Formula: m1v1 + m2v2 = (m1+m2)Vf