Scalars and Vectors

• What are the two types of quantities?

  Scalar and vector
• What defines a scalar quantity?

  Magnitude but no direction
• What defines a vector quantity?

  Both magnitude and direction
• How is distance defined?

  Measure of how far an object has travelled
• What type of quantity is distance?

  Scalar quantity
• How is displacement defined?

  Distance between two points including direction
• What type of quantity is displacement?

  Vector quantity
• What is the difference between distance and displacement?

  Displacement includes direction, distance does not
• How does the distance travelled by a student differ from their displacement?

  Distance includes all paths taken
• What is speed a measure of?

  Distance travelled per unit time
• What type of quantity is speed?

  Scalar quantity
• What is velocity a measure of?

  Displacement per unit time
• What type of quantity is velocity?

  Vector quantity
• Can an object have constant speed but changing velocity?

  Yes, if the object changes direction
• How are vectors represented?

  By an arrow indicating direction
• What does the length of a vector arrow represent?

  The magnitude of the vector
• How can vectors be combined?

  By adding them to produce a resultant vector
• What is the resultant vector sometimes known as?

  The net vector
• What methods can be used to add vectors?

  Calculation or scale drawing

  
• When can vector calculations be limited to two vectors?

  When the vectors are at right angles
• What theorem is used to find the magnitude of the resultant vector?

  Pythagoras' theorem

  
• How is the direction of the resultant vector found?

  From the angle it makes with the horizontal

  
• How can the angle of a resultant vector be calculated?

  Using trigonometry

  
• What are the steps to calculate the resultant vector using scale drawing?

  1. Link the vectors head-to-tail
  2. Draw the resultant vector
  3. Measure the length of the resultant vector
  4. Measure the angle of the resultant vector

  
• What should be noted about scale drawings?

  A scale may be given for the diagram
• How is the final answer from a scale drawing converted?

  Back to the units needed in the diagram
• What are the two methods to combine vectors?

  Triangle method and parallelogram method

  
• How do you combine vectors using the triangle method?

  Link the vectors head-to-tail

  
• How do you combine vectors using the parallelogram method?

  Link the vectors tail-to-tail and complete the parallelogram

  
• What is vector subtraction?

  When the negative value of one vector is added to the positive value of another vector
• What should students be confident with for vector addition?

  Pythagoras' Theorem and trigonometry