speed

• What is the difference between distance and displacement?

  Distance is scalar; displacement is vector
• What is the difference between speed and velocity?

  Speed is scalar; velocity is vector
• What factors can affect the speed at which someone walks, runs, or cycles?

  Age, fitness, terrain, and distance travelled
• What are typical speeds for a person walking, running, and cycling?

  1.5 m/s, 3.0 m/s, and 6.0 m/s
• What are typical speeds of a car and a train?

  Car: 13-30 m/s; Train: 50 m/s
• What is a typical speed for sound travelling in air?

  330 m/s
• What is acceleration?

  Change in velocity of an object per second
• What is the unit of acceleration?

  m/s²
• How can an object be accelerating even if it is travelling at a steady speed?

  If it is changing direction
• What is happening to an object if it has a negative acceleration?

  It is slowing down
• What information does the gradient of the line in a distance-time graph provide?

  It indicates speed of the object
• What information does the gradient of the line in a velocity-time graph provide?

  It indicates acceleration of the object
• How can the distance travelled by an object be found from its velocity-time graph?

  Calculate the area under the graph
• What is the acceleration of a free-falling object due to gravity?

  Approximately $9.81 \text{ m/s}^2$
• What is the name for the steady speed a falling object reaches when the resistive force is equal to its weight?

  Terminal velocity
• What is the general name for the frictional forces an object experiences when moving through a fluid?

  Drag
• In which direction does the drag on an object always act?

  Opposite to the direction of motion
• What happens to the drag on an object as its speed increases?

  The drag increases
• What can be done to reduce the drag on an object?

  Streamlining the object's shape
• What are the key concepts related to speed and motion?

  • Distance vs. Displacement
  • Speed vs. Velocity
  • Factors affecting speed
  • Typical speeds for walking, running, cycling
  • Typical speeds for cars and trains
  • Speed of sound in air
  • Acceleration and its unit
  • Negative acceleration
  • Distance-time and velocity-time graphs
  • Terminal velocity and drag
• What type of quantity is distance?

  Scalar quantity
• What does distance measure?

  How far an object moves
• What type of quantity is displacement?

  Vector quantity
• What does displacement include?

  Distance and direction from starting to finish point
• What is velocity?

  Speed in a given direction
• Why is velocity considered a vector quantity?

  It has both magnitude and direction
• When does an object's velocity change?

  If its direction changes
• What happens to an object's velocity when it moves in a circle?

  Its velocity is always changing
• What is acceleration?

  Change in velocity per second
• What is the unit of acceleration?

  m/s²
• When is an object considered to be accelerating?

  If its speed or direction changes
• How is acceleration calculated?

  Change in velocity divided by time
• What is uniform acceleration?

  Constant acceleration of an object
• What does negative acceleration indicate?

  The object is slowing down
• What is the equation for uniform acceleration?

  $v^2 =$$u^2 +$$2as$
• What is the formula for speed?

  $v =$$\frac{s}{t}$
• What are typical average speeds for walking, running, and cycling?

  1.5 m/s, 3 m/s, 6 m/s
• What is a typical speed for sound?

  300 m/s
• What happens to drag forces as an object's speed increases?

  Drag forces increase
• In which direction do drag forces act?

  Opposite to the object's movement