Interpreting Linear Graphs
Parallel and Perpendicular Lines
Rates
Gradient Intercept Form
100
30 SECONDS
What is the name of the relationship in which variables increase at the same, constant rate?
(a ) gradient relationship
(b ) linear relationship
(c ) intercept relationship
(d ) speed relationship
(b ) Linear Relationship
100
30 SECONDS
Fill in the blank
Parallel lines have ............... gradients
Equal
100
30 SECONDS
Which of these are not a rate?
(a ) Time
(b ) Speed
(c ) Gradient
(d ) Water flow
(a ) Time
100
30 SECONDS
When using the gradient-intercept form, what variables do we need to find to find the equation of the line?
Gradient, Y-intercept
200
2 MINUTES
A long-distance runner completes a training run, which is described by this graph.
What is the average speed for the first hour? 
10km/h
200
1 MINUTE
Perpendicular lines satisfy which of the following rules (there may be two answers):
(a ) m_1+m_2=1
(b ) m_1=m_2
(c ) m_1 *m_2=-1
(d ) m_1=-1/m_2
(c ) m_1 *m_2=-1
(d ) m_1=-1/m_2
200
1 MINUTE
Calculate the rate of water flow through a pipe when 20 litres flows in 2 hours.
10L/hr
200
1 MINUTE
What are the two formulas that can be used to find the gradient?
m = (rise)/(run)
= (y2-y1)/(x2-x1)
300
2 MINUTES
The weight of a wet sponge us reduced after it is left in the sun to dry.
What would you estimate the weight of the sponge to be after 3 hours?
200 grams
300
2 MINUTES
What is the equation of the line parallel to y=4x-5 and passes through (0,6)
y=4x+6
300
2 MINUTES
A large bottle with a long, narrow neck is being filled with water. What is the rate of waterflow in the first 20 seconds? Make sure you have the right units.
0.15 L/s
300
1 MINUTE
Find the equation of the line
y=2/3x-4
400
2 MINUTES
The graph shows the conversion between Country A and Country B's currency. What does 10 currencies of Country A convert to in Country B?
5 Currencies in Country B
400
3 MINUTES
What is the equation of the line perpendicular to y=3x+2 and passes through the point (1,1)?
y=-1/3x-2
400
1 MINUTE
Three students are making their way to school. Which student is the fastest?
Student B
400
2 MINUTES
What is the equation of the line that passes through (0,6) and (3,5).
y=-1/3x+6
500
3 MINUTES
What is the average speed of the train between 6 minutes and 21 minutes?
0.4km/min
500
2 MINUTES
Are these lines parallel, perpendicular or neither?
8y+2x=4 and y=4x+1
m_1 = -1/4 , m_2 =4
m_1*m_2 =-1/4*4=-1
Hence, the lines are perpendicular.
500
2 MINUTES
A tank of water starts off with 120L and it then it begins to drain. It drains at a rate of 200mL/min. How long will it take to drain the whole tank?
600 minutes or 10 hours
500
4 MINUTES
Which of the following points lie on the line y=2x+2
(a ) (2, 0)
(b ) (-1,3)
(c ) (4, 10)
(d ) (-5,-8)
(d ) (-5,-8)