Review
­
calculating average speed
­
determining distance when given average speed
­ drawing a distance time graph
Feb 7­11:25 AM
Speed Time Graph
­ a speed time graph indicates speed variations over a period of time
­ y axis is usually speed (dependent variable)
and x axis is time (independent variable)
­ the slope of the line will indicate changes in speed over the length of time used for measurement
Feb 7­11:27 AM
1
Speed Time Graph for a Uniform Object
Ex.
A car is on cruise control and travels at the following speed for 5 hours
Time (h)
1 2 3 4 5 Speed (km/h)
100 100 100 100 100 Draw the speed time graph
Feb 7­11:29 AM
Calculate area under graph: speed x time
What does this indicate?
Feb 7­11:33 AM
2
Discuss Movement
­ what does it mean if you say you move 2 metres?
­ how do you know where you went?
­ how do you know where you started?
­ determining movement depends on many factors
Feb 13­7:45 AM
Scalar and Vector Quantities (pgs 414 ­ 416)
(a) Scalar Quantity
­
a quantity that involves size but not direction
Ex.
weight
distance
time
­ we can be given a distance but not know where it takes us
Ex.
distance to Clarenville is 150km but we do not know what direction to go in
Feb 13­7:47 AM
3
(b) Vector Quantity
­ a quantity that includes both size and direction
Ex.
73 km, north
­ vector quantities are represented by symbols that include a small arrow over the quantity symbol Ex.
d
Feb 13­7:50 AM
­
vector quantities can include the following examples
(a) Position: separation and distance from a reference point
Ex.
152 km west of Bonavista
(b) Displacement: a change in position that includes the size of the quantity and the direction
Ex.
300 km south
Feb 13­9:44 AM
4
­ when we represent vectors we can use symbols or drawings
(1) Using Symbols
­ right the distance travelled
­ use compass points to express direction
Ex.
N, NW,NNW, SSE
­ direction goes in brackets
Ex.
52 km[N]
Feb 13­9:46 AM
(2) Drawing Vectors
­ vector is a line segment that represents size and direction of a vector quantity
Ex.
d = 75km[N]
75km
1cm=1.0km
­ state direction as a reference
­ draw line according to a scale or write size next to it
­ direction of line represents direction of vector and length of line represents size of vector
Feb 13­9:50 AM
5
Examples:
Scalar Quantity:
Distance: Bob travelled 5 km
Vector Quantity:
Position:
House
3km
Shop
5km
School
­ school is +5km from the shop
Displacement:
Bob travelled 10 km north
­ 10km[N]
10km
Feb 13­9:55 AM
Readings:
Pages 414 ­ 416
Exercises:
Page 417: #'s 1,2,3,5,6,7,8,13
Review Chapter 9
Pages 340­375
Feb 13­10:00 AM
6