1. Chapter 11 Speed & Other Compound Meaures

2. Learning Objectives Work with speed, distance & time problems Change units Read distance-time graphs Draw distance-time graphs Work with density, mass & volume problems Work with population density problems

3. Speed, Distance & Time Examples 1. A cheetah takes 4 seconds to travel 100m. What is its speed in m/s? 2. Lisa drives at an average speed of 80km/h for 3 hrs. What distance does she travel? 3. Lucy cycles at an average speed of 7km/h for 21km. How long does this take her? S D T

4. More S/D/T Examples 4. A train travels from London to York, a distance of 302.8km in 1hr 45mins. It then travels from York to Edinburgh, a distance of 334.7km in 2hr 30mins. Calculate the average speed of the train between London and Edinburgh.

5. Changing Units Hours minssecs Kmmcm ÷60 ×60 ÷60 ×60 ×1000 ÷1000÷100 ×100

6. More Changing Units Examples Examples 1. Henry completes a 200m race in 25 seconds. What is his speed in km/hr? 2. Find the total distance of a journey 10mins long if the speed is 1.2cm/min

7. Distance-Time Graph Always put time on the horizontal axis Always put distance on the vertical axis The speed is the gradient To find the gradient pick 2 points. Subtract the distance values Subtract the time values Speed = Distance÷Time

8. Drawing Distance-Time Graphs 1. A bus journey is made up of the following stages: 1000m for 1 st 50 secs Rest for the next 50 secs 1700m for the next 50 secs Rest for 70 secs At 250 secs the distance is 3000m Rest for 30 secs Journey ends with distance 3600m at time 400 secs Draw a graph to represent this journey.

9. Density, Mass & Volume Examples 1. A block of metal has mass 500g and volume 400cm 3. Calculate the density of the metal. 2. The density of a certain metal is 3.5g/cm3. A block of the metal has volume 1000cm 3. Calculate the mass of the block. M D V

10. More M/D/V Examples 3. Metal A has density 3g/cm3 and metal B has density 2g/cm3. 600g of metal A and 300g of metal B are melted down and mixed to make an alloy which is cast into a block. (a) Calculate the volume of the block (b) Calculate the density of the alloy.

11. Population Density Examples 1. The population of Cumbria is 4.897×10 5. The area of Cumbria is 6824km 2. The population of Surrey is 1.036×10 6. The area of Surrey is 1677km 2. Which country has the greater population density? Pop Pop D Area