physics ⋆౨ৎ˚🪐⟡˖

• Force

  A push or pull that acts on an object due to its interaction with another object
• Newtons


  The unit used to measure force
• Forces


  • Have both magnitude (measured in newtons) and direction
  • Are classified as vector quantities
• Types of forces


  • Contact forces
  • Non-contact forces
• Contact forces


  Forces where the two objects are physically touching
• Non-contact forces


  Forces that don't require the two objects to be touching
• Types of non-contact forces

  • Gravitational force
  • Magnetic force
  • Electrostatic force
• Non-contact forces


  • Act through empty space and can be thought of as fields of influence around an object
  • The strength of the force decreases as the objects get further apart
• Scalar quantity


  Physical quantity that only has a magnitude but no direction
• Scalar quantities


  • Speed
  • Distance
  • Mass
  • Temperature
  • Time
• Vector quantity


  Physical quantity that has both a magnitude and a direction
• Vector quantities


  • Velocity
  • Displacement
  • Acceleration
  • Force
  • Momentum
• Representing vectors


  1. Use arrows

  2. Length of arrow indicates magnitude

  3. Direction arrow is pointing indicates direction
• Free body diagram


  A simple diagram that shows all the forces acting on a particular object
• Free body diagrams


  • Use force arrows to represent the forces acting on an object
  • Each force arrow has a magnitude (size) and direction
• Calculating the resultant force

  1. Identify the horizontal and vertical components of the forces

  2. Subtract the opposing forces in each direction

  3. The remaining force is the resultant force
• If the horizontal and vertical components are balanced

  The object is in equilibrium (no resultant force)
• The magnitude of each force is measured in Newtons
• Waves


  Transfer energy from one place to another, but do not transfer any matter
• Waves


  • Vibrate or oscillate
  • Can be interpreted as meaningful information (e.g. images, tunes)
• Displacement


  How far the wave has oscillated from the equilibrium point
• Amplitude


  The maximum displacement of the wave
• Wavelength


  The distance of one entire oscillation
• Crest


  The top of the wave
• Trough


  The bottom of the wave
• Time period


  The time it takes for one complete oscillation
• Calculating frequency


  Frequency = 1 / Time period
• Calculating wave speed


  Wave speed = Wavelength x Frequency
• Transverse waves


  • Oscillations are perpendicular to the direction of energy transfer
  • Examples: electromagnetic waves, water waves, string waves
• Longitudinal waves


  • Oscillations are parallel to the direction of energy transfer
  • Examples: sound waves, seismic P-waves
• Energy can be transferred from one place to another
• When light waves pass from phone screen to your eye, or when sound waves pass from speakers to your ear, only energy is being transferred
• For waves to travel from one place to another, the waves vibrate or oscillate
• Wavelength


  The distance of one entire oscillation
• Displacement


  How far from the equilibrium point the wave has excited
• Period (T)


  The time it takes for one complete oscillation
• Frequency (f)


  The number of oscillations per second
• Transverse waves have oscillations that are perpendicular to the direction of energy transfer
• Transverse waves


  • Electromagnetic waves like light & radio waves
  • Ripples on water
  • Waves of strings on a guitar
• Longitudinal waves have oscillations that are parallel to the direction of energy transfer