Science

• Force


  A vector quantity that represents the interaction between two objects, causing a change in their motion
• SI unit of force


  Newton (N)
• Key terms associated with force and movement


  • Mass
  • Acceleration
  • Velocity
  • Momentum
  • Inertia
• Balanced forces


  Net force acting on an object is zero, resulting in no change in its motion
• Unbalanced forces


  Cause a change in an object's motion, resulting in acceleration or deceleration
• Force is measured in Newtons (N), named after Sir Isaac Newton, the pioneer of classical mechanics
• One Newton is defined as the force required to accelerate a one-kilogram mass at a rate of one meter per second squared
• Distance


  The total length of the path traveled by an object, regardless of direction
• Displacement


  The vector quantity that represents the change in position of an object from its initial to final position in a straight line, considering both magnitude and direction
• Speed


  A scalar quantity that measures the rate at which an object covers distance, calculated by dividing the distance traveled by the time taken, expressed in meters per second (m/s)
• Speed calculations and manipulations of formula


  1. Speed = Distance / Time

  2. Distance = Speed x Time

  3. Time = Distance / Speed
• Speed triangle


  A graphical method used to calculate speed, distance, and time
• Analyse speed data using distance/time graphs

  1. Determine the speed of the object from the slope of the graph

  2. Horizontal line indicates the object is at rest

  3. Straight diagonal line indicates constant speed

  4. Curved line indicates acceleration or deceleration
• Velocity


  A vector quantity representing both speed and direction
• Velocity calculations


  Velocity = Displacement / Time
• Acceleration


  The rate of change of velocity with respect to time
• Acceleration calculations


  Acceleration = (Final velocity - Initial velocity) / Time taken
• Acceleration units


  Meters per second squared (m/s^2)
• Ticker timers


  Devices used to measure time intervals in physics experiments, particularly for studying motion
• Inertia


  The tendency of an object to resist changes in its state of motion
• Objects with greater mass have greater inertia, making them more resistant to changes in motion
• Seat belts, head restraints, airbags


  • Safety features in vehicles designed to reduce the risk of injury in accidents
• Momentum


  The product of an object's mass and velocity, conserved in collisions
• Trolleys and crash test dummies are used in physics experiments to model car accidents and study the effects of collisions on occupants
• Newton's Second Law


  The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass, expressed as F = ma
• F = ma calculations


  Calculate the net force acting on an object by multiplying its mass by its acceleration
• Crumple zones


  • Regions of a vehicle designed to deform and absorb energy in the event of a collision
• Newton's Third Law


  For every action, there is an equal and opposite reaction
• Convection


  The transfer of heat energy through the movement of fluids (liquids or gases)
• Conduction


  The transfer of heat energy through direct contact between particles of matter
• Waves carry energy, not matter
• Transverse waves


  Waves in which the particles of the medium move perpendicular to the direction of the wave propagation
• Longitudinal/compression waves


  Waves in which the particles of the medium move parallel to the direction of wave propagation
• Crest and trough


  In a transverse wave, the crest is the highest point, and the trough is the lowest point
• Frequency


  The number of complete wave cycles that pass a given point in one second, measured in Hertz (Hz)
• Amplitude


  The maximum displacement of particles from their equilibrium position in a wave
• Wavelength


  The distance between two consecutive points in a wave that are in phase
• Period


  The time it takes for one complete cycle to pass a given point
• Wave calculations and manipulation of formula


  Speed = Frequency x Wavelength
• Sound travels as longitudinal waves