SCIENCE 9 PHYSICS

• Momentum


  A measure of the difficulty of stopping or starting to move an object, directly affected by mass and velocity
• Physical Quantities


  Quantities that can be measured, have numerical magnitude and unit
• Types of Physical Quantities

  • Scalar Quantities (magnitude only)
  • Vector Quantities (magnitude and direction)
• Scalar Quantities


  Have magnitude only
• Vector Quantities


  Have magnitude and direction
• Distance


  Has no direction
• Displacement


  Has direction
• Derived Unit


  Combination of two or more units
• Basic Unit


  Has no combination
• Collision


  An encounter between two objects resulting in exchange of impulse and momentum, occurs when two objects come in direct contact
• During a collision, external forces (like friction) are negligible due to the short period of time
• Law of Conservation of Momentum


  The total momentum of the system before the collision is equal to the momentum of the system after the collision
• Types of Collision

  • Elastic Collision (total kinetic energy does not change)
  • Inelastic Collision (total kinetic energy changes or is lost)
• Perfectly Inelastic Collision


  Objects stick together after collision
• Mechanical Energy = Potential Energy + Kinetic Energy
• Units and Scientists' Names

  • Newton (N = kg·m/s²)
  • Joule (J = kg·m²/s²)
  • Pascal (Pa = N/m²)
  • Watt (W = J/s)
• Energy - the capacity to do work
• Work - the product of force and distance/displacement
• Momentum change because of Impulse
• Equation 1 of Impulse:

  I=f × t
• Equation 2 of Impulse:

  I=change in momentum
• Force should have distance and time
• Elastic Collision - which the total kinetic energy of the system does not change or not lost and colliding objects bounce off after collision
• Inelastic Collision - which the total kinetic energy of the system changes or lost during the process. The lost kinetic energy is transformed into thermal energy, sound energy, and material deformation
• Formula of Energy:

  E=mc²

  where:

  m=mass

  c²=speed of light
• Formula of momentum:

  p=mv

  Where:

  p=momentum

  m=mass(kg)

  v=velocity(m/s)
• Formula of work:

  w=f×d

  Where:

  F=force(kg.m/s²)

  d=distance
• Potential Energy - objects at rest
• Formula of potential energy:

  PE=mgh

  Where:

  m=mass(kg)

  g=gravitational acceleration (9.81m/s)

  h=height(m)
• Kinetic Energy - objects in motion
• Formula of Kinetic Energy:

  KE=½mv²

  where:

  ½ is constant

  m=mass

  v=velocity
• Law of conservation


  Remains
• Energy Transpormation increases the efficiency of a hea engine
• Heat engine


  Converts heat into work
• Transmission lines


  • Allows electricity to reach distant places
• Power plant


  • Generates electricity
• The individual momentum of objects in an inclated stem during the Collision is remain constant
• Thermodynamics


  The science of energy, specifically heat and work
• Thermo


  Greek therme for heat
• Dynamica


  Greek for dynamikos, meaning powerful