Motion

• Define distance 


  The total length that an object travels
• What kind of quantity is distance?

  It is a scalar quantity, so it cannot be negative. It only takes into account the magnitude of the distance.
• Define displacement 


  The distance travelled in a particular direction
• What kind of quantity is displacement?

  A vector quantity
• Explain the similarities and differences between distance and

  SIMILARITIES: They both are measured in metres, they both take into account the distance travelled

  DIFFERENCES: Distance is a scalar quantity and displacement is a vector quantity, displacement takes into account the direction of the object whereas distance doesn’t, displacement can be negative but distance cant be
• How would we measure displacement between points A and B?

  It would be measured using a straight line between the two points
• Define the average speed

  The total distance travelled/time
• What kind of quantity is speed?

  A scalar quantity
• How do you work out average velocity

  The total displacement/time
• If an object moves in a circular path, what will its displacement be?

  Zero
• If an object moves in a circular path, what will its distance be?

  Equal to the circumference of the circle
• How can we define the instantaneous velocity?

  It is the speed of the car over a very short period of time.
• How can we determine the instantaneous velocity at a certain point?

  By drawing a tangent to the graph at that point, and determine its gradient
• Describe the relationship between the gradient and instantaneous velocity 


  The greater the gradient, the greater the instantaneous velocity
• Define acceleration 


  The rate of change of velocity
• What is the equation for acceleration?

  The change in velocity/the change in time
• What is the base unit for acceleration?

  ms^-2
• If I dropped an object, what would it’s acceleration be in the absence of air resistance?

  9.81, this is known as acceleration due to free fall, ‘g’, it falls at a rate equal to the gravitational acceleration on earth
• What kind of shape would you expect from a velocity-time graph, and what does this tell you about its relationship?

  A straight line. This shows that there is a directly proportional relationship between velocity and time
• How do we work out of the acceleration from a velocity-time graph?

  By calculating the gradient
• What does a negative velocity tell you?

  A change in direction
• What does the gradient represent in a displacement against time?

  The velocity
• What does the gradient represent in a velocity against time graph?

  Acceleration
• What does the area underneath a velocity against time graph represent?

  Displacement
• What are the limitations of s=v x t

  The velocity needs to be constant
• When can you use the SUVAT equations?

  When acceleration is constant
• How is distance defined in this context?

  Length of the path traveled by an object
• What type of quantity is distance?

  Scalar quantity
• What does distance measure?

  The amount of length traveled by an object
• How is displacement different from distance?

  Displacement includes direction
• What type of quantity is displacement?

  Vector quantity
• How is a vector quantity represented?

  With an arrow indicating size and direction
• What is the displacement from point A to point B?

  A straight line between points A and B
• What are the definitions of average speed and average velocity?

  • Average speed: Total distance traveled / time
  • Average velocity: Displacement / time
• How do you calculate average speed?

  Total distance traveled divided by time
• How do you calculate average velocity?

  Displacement divided by time
• What happens to displacement if an object returns to its starting point?

  Displacement becomes zero
• What is the distance traveled in a full circular path?

  $2\pi r$
• Why is the average speed of the aircraft not the same as the magnitude of its average velocity?

  Distance and displacement are different
• How do you calculate the speed of Io in orbit?

  Distance traveled divided by time