physics

• Scalar


  Described only by a magnitude (a number/value)
• Vector


  Described by both magnitude and direction
• Distance


  Scalar: how far something moved

  
• Displacement


  Vector: how far something actually is
• Speed


  Scalar: distance over time
• Velocity


  Vector: displacement over time
• Acceleration


  Vector: change in velocity over time
• Free fall


  • Acceleration is constant -9.81 m/s²
  • Vertical and horizontal motion are independent
• Projectile motion


  • Horizontal velocity is constant, vertical motion accelerates down at -9.81 m/s²
• Relative motion


  Motion is dependent on the frame of reference of the observer
• Newton's 1st law


  A body at rest or uniform motion will continue to be at rest or uniform motion until and unless a net external force acts on it
• Newton's 2nd law


  The acceleration of an object depends on the mass of the object and the amount of force applied
• Newton's 3rd law


  There is an equal and opposite reaction for every action
• Types of forces


  • Contact forces: Normal, Frictional, Tensional, Weight
  • Non-contact forces: Electric, Magnetic
• Net force


  The sum of all contact and non-contact forces acting on an object
• Power


  The rate of doing work or the energy consumed per time
• Kinetic energy


  The energy in motion
• Types of energy


  • Potential (gravitational, elastic), Chemical, Mechanical, Electrical, Magnetic, Nuclear, Heat
• Fluid mechanics


  The study of the behaviour of fluids at rest or in motion
• Fluid


  Liquids and gases that can deform easily and flow
• Density


  Mass per unit volume
• Pressure


  Normal force per unit area

  
• Pascal's principle


  When a change in pressure is applied to an enclosed fluid, it is transmitted undiminished to all portions of the fluid and to the walls of its container
• SI unit of pressure

  Pa (pascal)
• Instruments used in measuring pressure

  Manometers and barometers
• p = pₒ + ρhg
• Buoyant Force


  The upward force on any object in any fluid
• Mechanical Wave


  Any disturbance that propagates from one region to another travels within some material called medium

  
• Types of Mechanical Waves

  • Transverse Wave – displacements of the medium are perpendicular to the wave direction
  • Longitudinal Wave – displacements of the medium are parallel to the wave direction

  
• Wave Properties


  • Wave Speed (v)
  • Period (T)
  • Frequency (f)
  • Wavelength (λ)
  • Amplitude (A)

  
• Types of Interference


  • Constructive interference – occurs when interfering waves have displacements in the same direction
  • Destructive interference – occurs when interfering waves have displacements in the opposite direction

  
• Principle of Superposition


  At any point where two or more waves overlap, the total displacement is the sum of the displacements of the individual waves
• Acoustics


  The study of sound waves
• Types of Sound Waves

  • Audible range of human ear: 20 to 20,000 Hz
  • Ultrasonic – frequencies above the range of human hearing
  • Infrasonic – frequencies below the range of human hearing
• Sound Intensity (I)


  The time average rate at which energy is transported by the wave, per unit area, expressed in W/m²

  
• Sound Intensity Level (β)

  A log-arithmic measure of a sound wave's intensity, measured relative to I₀, an arbitrary intensity defined to be 10⁻¹² W/m², expressed in decibels (dB)
• Hearing Perception


  • Loudness – perception of sound intensity
  • Pitch – perception of the frequency of a sound
  • Timbre – number and relative intensity of multiple sound frequencies; tone color, quality
  • Noise – a combination of all frequencies
• Optics


  The study of the behavior of light and other electromagnetic waves

  
• Index of refraction / refraction index


  The ratio of the speed of light c in vacuum to the speed v in the material. n = c/v, where n=1 for vacuum and n>1 for all other materials.

  
• Thermodynamics


  The study of energy transformations involving heat, mechanical work, and other aspects of energy and how these transformations relate to the properties of matter