“The end is near! Just around the corner, turn left and then two rights ”

 SCALAR  A quantity that has MAGNITUDE (size), and UNITS but NO direction.  Ex: distance (d = 10 km), time (t = 2 min), speed (v = 25 m/s)  VECTOR (symbolized by arrow)  A quantity that has MAGNITUDE (size), UNITS, and DIRECTION.  Ex: displacement (d = 10 km [E]), velocity (v = 25 m/s [N])

 DISTANCE (symbol:  d)  Distance is a scalar quantity.  Measured in m or km.  A measure of the TOTAL TRAVEL of an object, regardless of direction.  Example: Andrew walks for 100 m on a circular track, and then runs for 400 m back to the start position. What is his total distance travelled? d 1 = 100m d 2 = 400 m d T = d 1 + d 2 = 500 m

 DISPLACEMENT (symbol:  d)LINKLINK  Displacement is a vector quantity.  Measured in m or km.  A measure of the shortest path from start point (aka reference point) to finish point; straight line path.  Example: What is Andrew’s displacement? d T = 0 m His start and finish point are the same point.

Which colour arrow(s) represents:  Distance?  Displacement?

 REFERENCE POINT  Original start position “0”, all directions are given from the reference point.  Ex: 0d = 2 m [E]  POSITION  An object’s displacement from the reference point.  If more than 1 position, use symbols d 1, d 2, d 3,etc. 2 m REFERENCE POINT POSITION

The red arrow represents the displacement Notice that distance is the entire route travelled.

 Reference Point?  Distance?  Displacement?

 SPEED (symbol:  v)  Speed is a scalar quantity.  Measured in m/s or km/h.  A measure of the distance per unit time.  TYPES OF SPEED: Constant speed Instantaneous speed Average speed

 Example:  Super Physics Guy (SPG) flew to Corner Brook from St. John’s, a distance of 750 km [W] in a time of 4.6 h. He then went to his friend’s house, km [E] in a time of 15.0 min. What was his average speed?

 VELOCITY (symbol:  v)  Velocity is a vector quantity.  Measured in m/s or km/h.  A measure of the displacement per unit time.

 Example:  In the above example, what was SPG’s average velocity?

 Acceleration can be a SCALAR or VECTOR quantity.  Measured in m/s 2 or km/h/s.  A measure of an object’s change in speed OR velocity per unit time.

 What are some typical descriptors we use for direction?  Draw these on your sheet. N W S E D RL U X Y Z

 1-DIMENSIONAL VECTORS are vectors in the SAME PLANE.  EXAMPLE:  X PLANE: 2 m [E], 5 m [L]  Y PLANE:3 m [D], 6 m [N]  Notice that directions are always expressed using SQUARE BRACKETS.  Example: 25 m [N25 o E]  When calculating vectors in 1-dimension, we simply assign positives (+) and negatives (-) to our direction systems.  POSITIVE is always assigned to: [N], [U], [E], [R]  NEGATIVE is always assigned to: [S], [D], [W], [L]  We can then calculate RESULTANT or TOTAL displacement by adding together our positive and negative individual vector values.

DRAW A SKETCH! !!!!!!!!

 Example 1:  McLennon is at his locker when the bell rings and he goes 20.0 m [E] to Science 1206 class. He does not have his homework done, so he then goes 50.0 m [W] to the office. What is his total displacement?

 Example 2:  Anna goes 20 m [U], 15 m [D], 30 m [U], and 5 m [U] on a rock wall. What is her resultant displacement?

 Example 3:  A Codroy Valley WILD BALONEY was sighted running through the forest. It ran 45 km[E], and then 65 km[W] in 2 hours and 15 min. What was its  DISTANCE?  AVERAGE SPEED?  DISPLACEMENT?  AVERAGE VELOCITY?

 Please complete WORKSHEETS 21 & 22 on pages 51 and 52 for homework.

 WHAT IS A VECTOR?  An arrow that accurately indicates SIZE and DIRECTION of motion.  It has a TIP and a TAIL.  EXAMPLE:  There are 2 types of vectors:  POSITION VECTOR  RESULTANT VECTOR TAIL TIP

 POSITION VECTOR  Vectors that are connected to each other, starting at reference point, using the tip-to-tail method.  EXAMPLE:  RESULTANT VECTOR – (Hint: draw as a dashed or double line)  The resultant vector indicates the resultant displacement or velocity.  It is ALWAYS DRAWN from reference point (start) to finish.  It indicates our CHANGE in POSITION from START to FINISH (the way the crow flies!).  For the resultant vector, DIRECTION is always indicated FROM the reference point.  EXAMPLE: d1d1 d2d2 d1d1 d2d2 dRdR d1d1 d2d2 Add vectors tip to tail. Resultant vector drawn from reference point to end point

STEPS  Indicate VECTOR DIRECTION using a bearing system.  Example:  Use a SCALE to indicate RELATIVE SIZE of vectors.  Try to use a scale that is easily converted.  EXAMPLE: 1 cm = 10 km  Create a REFERENCE POINT and use a PROTRACTOR, RULER, and your SCALE to start your first POSITION VECTOR.

STEPS...  Connect remaining VECTORS using TIP-TO-TAIL METHOD.  Draw RESULTANT VECTOR from REFERENCE POINT (START) to FINISH.  Measure resultant vector size and angle to determine resultant displacement or resultant velocity.

 20 km [E]  20 km [N]  20 km [E20 o N] (reads “East 20 degrees North”)

2.0 m [N] m [S] 250 m [S] m [W]

48 km [E40 o S] km [W]

500.0 m [N] m [S50 o E]

0.50 km [N20 o E] km [W] km [W50 o S]

 Please complete WORKSHEETS 23 & 24.

Closed Book Test on Unit 3 Part 2 Booklet  Topics include:  Acceleration  Speed-Time Graphs  Vector and Scalar Comparisons Distance vs. Displacement Average speed vs. Average velocity  Vector Diagrams  Test Format:  Multiple Choice  Acceleration Calculations  Speed-Time Graph  Vector Diagram  TEST DATE :______________