Presentation on theme: "Internal 3 Credits DO NOW: Turn to page 177 and do problem 9."— Presentation transcript:
Internal 3 Credits DO NOW: Turn to page 177 and do problem 9.
What is it? A rate compares 2 quantities measured in different units. Example of rates? 45 wpm, 80 km/h,
The graph on the right shows distance travelled over time. Let’s calculate the gradient. Gradient = Rise / Run 160 km / 2 h = 80 km / h 2 h 160 km The gradient of the graph is the rate!
This shows B is growing at a faster rate. The gradient for the line in B is steeper than for the line in A. How do we know that it is steeper? Population 1975 B Population 1975 A The graph shows the growth in population for two towns. The gradient for the line in B is steeper than for the line in A. Which town is growing at a faster rate?
Town A grows from to in in 2005 The population increase per year is = 667 people per year This is an increase of in 30 years. The graph shows the growth in population for 2 towns.What are the rates? Town B grows from to in 2005 The population increase per year is = 1000 people per year This is an increase of in 30 years in Population 1975 B Population 1975 A
Turn to page 182 and do the following problems: 1, 3, 9, 10, 13, 16, 21
Speed is the rate at which distances travelled changes over time. Usually called Velocity. Units: Distance – km or m Time – h or s Velocity – km/h or m/s
For this level, we only work with average speed. For example: Car travels 360 km over 4 hours, we say that the average speed is 360/4 = 90 km/h (even though the car would have travelled faster over some sections)
Distance = Velocity * Time Velocity (or speed) = distance / time Time = Distance / Velocity (or speed) Dist. Vel.Time