physics

• What is kinematics concerned with?

  Kinematics is the branch of physics concerned with the motion of objects without reference to the forces that cause the motion.
• How does kinematics predict motion?

  Kinematics predicts different parts of motion using other parts of the motion without needing to know the nature of the object or the forces acting on it.
• What are the key terms used to describe the motion of bodies through space and time?

  • Position
  • Velocity
  • Acceleration
• What is displacement?


  Displacement is the change of position.
• What is velocity?


  Velocity is the rate of change of position.
• What is acceleration?


  Acceleration is the rate of change of velocity.
• What does it mean if acceleration has the same sign as velocity?

  If acceleration has the same sign as velocity, the object is getting faster.
• What does it mean if acceleration has the opposite sign to velocity?

  If acceleration has the opposite sign to velocity, the object is getting slower.
• Why does a change in direction cause acceleration?

  A change in direction causes acceleration because it changes the displacement, which changes the velocity over time.
• What is the difference between distance and displacement?

  • Distance: A scalar quantity that refers to how much ground an object has covered during its motion.
  • Displacement: A vector quantity that refers to an object’s overall change in position.
• What is the rule for defining motion on an axis?

  The rule is to define a 0 point and a positive and negative direction, both of which are arbitrary.
• What are instantaneous and average values in kinematics?

  • Instantaneous: Speed/velocity/acceleration at any given time.
  • Average: Calculated using equations.
• How do you translate between position-time graphs and velocity-time graphs?

  • Position-time to velocity-time: Gradient of p-t graph is equal to velocity.
  • Velocity-time to position-time: Area under v-t graph is equal to displacement.
• What are the kinematic equations and their variables?


  | Variable | Unit |

  | --- | --- |

  | Displacement (S) | m |

  | Initial velocity (U) | m/s |

  | Final velocity (V) | m/s |

  | Acceleration (a) | m/s² |

  | Time (t) | s |

  
  

  Equations:

  1. \( v = u + at \)

  2. \( v = \frac{(u+v)}{2}t \)

  3. \( s = ut + 0.5at^2 \)

  4. \( v^2 = u^2 + 2as \)
• What is a projectile in physics?

  A projectile is a particle moving freely, non-powered, under gravity, in a two-dimensional plane.
• What is the time of flight in projectile motion?

  The time of flight is how long the projectile is in the air, with the time to maximum height being half of the total time.
• What is the maximum height attained in projectile motion?

  The maximum height is when the object is momentarily at rest, which occurs when the vertical velocity component equals zero.
• What are the components of projectile motion?

  Projectile motion has vertical and horizontal components that are independent of each other, with time being the only variable that is the same for both.
• What is the trigonometric relationship in projectile motion?

  In projectile motion, the vertical component is the opposite side, the horizontal component is the adjacent side, and the resultant velocity is the hypotenuse of the projectile triangle.
• What does "launched horizontally" mean in projectile motion?

  "Launched horizontally" means there is no initial vertical velocity.
• What happens if an object lands at the same height it started with in projectile motion?

  If an object lands at the same height it started with, its y-displacement is 0 m.
• What is fluid resistance?

  Fluid resistance refers to the effects of gases and liquids on the motion of a body.
• What are viscous drag and air resistance?

  Viscous drag and air resistance are the resistive, frictional forces an object experiences when moving through a fluid.
• What are the characteristics of frictional forces?

  • Always act in the opposite direction to the movement of the object.
  • Always slow an object down or keep its speed constant.
  • Always transfer energy away from the object to its surroundings.
• What is lift in fluid dynamics?

  Lift is an upward force acting on an object in a fluid, which is perpendicular to the fluid flow.
• How do drag forces behave in relation to lift?

  Drag forces always act in the opposite direction to lift and increase with the speed of the object.
• What factors are affected by fluid resistance?

  • Time of flight
  • Horizontal velocity
  • Horizontal acceleration
  • Range
  • Shape of trajectory
• What is the effect of air resistance on projectile motion?

  Air resistance causes the flight time to shorten and the shape of the trajectory to be steeper on the way down.
• How can the angle and launch speed of a projectile be varied?

  The angle and launch speed of a projectile can be varied to cover a greater range or to reach a greater maximum height.
• What is terminal speed?

  • The frictional force from fluid resistance increases as the body accelerates.
  • Drag forces also increase with velocity.
  • When the drag force equals the weight of the body, it will fall at a constant velocity, known as terminal velocity.