Dynamics

• Average Speed


  Distance traveled per unit time
• SI Unit of Average Speed

  ms-1 (metres per second)
• Measurement of Average Speed

  Requires distance and time measurement
• Instantaneous Speed


  Speed at a specific instant
• Light Gate


  Device to measure instantaneous speed accurately
• Scalar Quantity


  Magnitude and unit only, e.g., time = 220 s
• Vector Quantity


  Magnitude, unit, and direction, e.g., Force = 800 N upwards
• Displacement


  Vector quantity from start to end point
• Distance


  Scalar quantity, total path length
• Speed vs. Velocity


  Speed is scalar, velocity is vector with direction
• Acceleration


  Change in velocity per unit time
• Acceleration Equation


  Final velocity - Initial velocity / Time
• Deceleration


  Acceleration opposite to motion, speed decreases
• Velocity-Time Graphs


  Display motion details, calculate acceleration, distance, average velocity
• Constant Velocity


  Uniform motion, no acceleration
• Constant Acceleration


  Uniformly increasing velocity
• Displacement Calculation


  Area under velocity-time graph
• Average Velocity


  Total displacement divided by total time
• Newton's Laws


  Laws describing motion and forces
• Force Effects


  Changes shape, speed, or direction of an object
• Mass vs. Weight


  Mass is amount of matter, weight is force due to gravity
• Gravitational Field Strength


  Force gravity exerts per unit mass
• Friction


  Resistive force opposing object motion
• Air Resistance


  Friction due to collisions with air particles
• Increasing Friction


  Methods to enhance friction for slowing down
• Decreasing Friction


  Techniques to reduce friction for smoother movement
• Force as a Vector

  Force quantity with direction determining effect
• Balanced Forces


  Equal forces in opposite directions resulting in no net force
• Newton's First Law


  Object remains at rest or constant velocity unless acted upon
• Balanced forces


  Forces keeping an object stationary or moving at a constant velocity in a straight line.
• Newton's Second Law


  Acceleration of an object when an unbalanced force is applied, related to force and mass.
• Free body diagrams


  Illustrations showing forces acting on an object, aiding in calculating resultant force.
• Resultant force


  Combined force acting on an object, calculated by subtracting forces in opposite directions.
• Mass


  Amount of matter in an object, influencing acceleration when force is applied.
• Force


  Push or pull acting on an object, measured in Newtons (N).
• Free-fall


  Object accelerating downwards under the influence of gravity with no opposing forces.
• Terminal velocity


  Constant velocity reached when air resistance balances the weight of a falling object.
• Newton's Third Law


  Principle stating that for every action, there is an equal and opposite reaction.
• Weight


  Force of gravity acting on an object, calculated as mass multiplied by gravitational field strength.
• Gravitational field strength


  Force per unit mass acting on an object in a gravitational field, influencing acceleration.