P9 Motion

• What is the definition of acceleration?

  Change in velocity per second
• What is the definition of deceleration?

  Negative acceleration, slowing down
• What is the definition of displacement?

  Distance travelled in a straight line
• What is the definition of gradient?

  Steepness of a line on a graph
• What is the definition of speed?

  Distance travelled per unit time
• What is the definition of tangent?

  A line touching a curve at one point
• What is the definition of uniform acceleration?

  Constant acceleration over time
• What is the definition of velocity?

  Speed in a given direction
• How can displacement be calculated from a velocity-time graph?

  • Calculate area under the graph
  • Measure or count squares
• What is the formula for distance travelled?

  Distance = speed × time
• What is the symbol for distance?


  s
• What is the symbol for speed?

  v
• What is average speed?

  Total distance divided by total time
• What is a typical running speed?

  Approximately 3 m/s
• What is a typical cycling speed?

  Approximately 6 m/s
• What is a typical walking speed?

  Approximately 1.5 m/s
• What is a typical speed of sound?

  Approximately 300 m/s
• Why is velocity considered a vector quantity?

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

  If its direction changes, even at constant speed
• What happens to the velocity of an object moving in a circle?

  Its velocity is always changing
• How can motion sensors be used in experiments?

  To record changes in an object's velocity
• What does a straight line on a velocity-time graph indicate?

  Constant acceleration
• What does a curved line on a velocity-time graph indicate?

  Changing acceleration
• What does a horizontal line on a velocity-time graph indicate?

  Constant velocity
• What does the gradient of a distance-time graph represent?

  The object's speed
• What does the gradient of a displacement-time graph represent?

  Velocity

  
• How can speed be found from a distance-time graph if the object is accelerating?

  Draw a tangent and find the gradient
• What does a steeper graph indicate in a displacement-time graph?

  Greater velocity
• What does the gradient of a velocity-time graph represent?

  The object's acceleration
• What does a flat section on a displacement-time graph indicate?

  Zero velocity (stopped)
• How can distance travelled be found from a velocity-time graph?

  Calculate the area under the graph
• What does a negative gradient on a displacement-time graph signify?

  Returning to start point
• What is the unit of acceleration?

  m/s²
• What does the gradient of a velocity-time graph represent?

  Acceleration

  
• What does a negative gradient on a velocity-time graph indicate?

  Deceleration

  
• How can an object be accelerating while travelling at a steady speed?

  If it is changing direction
• What does a flat section on a velocity-time graph represent?

  Steady velocity (NOT STOPPED)

  
• What does negative acceleration indicate?

  The object is slowing down
• What does the equation \( v^2 - u^2 = 2as \) represent?

  Uniform acceleration relationship
• What does the area under a velocity-time graph represent?

  Distance travelled