Constant vs Average speed

1. Constant Versus Average Speed

2. Ant #1 crawled 12 inches in 1 second. Ant #2 crawled 24 inches in 1 second. Compare the speed of the ants- which one i s faster? How does the distance compare?

3. DIRECTLY PROPORTIONAL TO DISTANCE Greater speed (faster)= more distance Less speed (slower) = less distance

4. The top plane flew 220 meters in 1 second. A bottom plane flew 220 meters in 2 seconds. Compare their speeds-which plane is faster? How do the times compare?

5. SPEED IS…. Inversely Proportional to TIME Greater speed, less time Less speed, more time

6. CONSTANT SPEED SPEED THAT DOES NOT CHANGE

7. CONSTANT SPEED

8. AVERAGE SPEED AVERAGE = total distance traveled SPEED total time

9. AVERAGE SPEED

10. AVERAGE SPEED

11. A car travels 32 km during the first 2 hours . Then it travels 13 km in the next hour . What is the average speed of the car? ANSWER: Avg speed= total distance/total time total distance = 32 km + 13 km = 45 km total time = 2 h + 1h = 3 hr Avg speed = 45 km/3 hr Avg speed = 15 km/hr

12. CONSTANT SPEED

13. Definitions: A change in position in a certain amount of time is __________. __________________ is the rate at which an object moves and is determined by dividing ____________ by _____________. _________________________ is speed that does not change. _________________________ is calculated by dividing the total distance by the total time .

14. SPEED WORKSHEET Complete for homework

15. Calculate the speed at each point on the y-axis Time (min) 20 40 60 80 100 120 Distance (km) Speed (km/min) 2. Describe the motion shown in the graph: 3.Calculate the average speed for the graph – how does this value compare to your calculations above? 3. How far would Ken travel if he walked for another hour (60 minutes)?

16. Calculate the speed at each point on the y-axis Time (min) 20 40 60 80 100 120 Distance (km) 1.5 3 4.5 6 7.5 9 Speed (km/min) 0.075 0.075 0.075 0.075 0.075 0.075 2. Describe the motion shown in the graph: 3.Calculate the average speed for the graph – how does this value compare to your calculations above? 0.075 km/min 3. How far would Ken travel if he walked for another hour (60 minutes)? 13.5 km

17. 5.Describe the motion shown in the graph 6.How many different rates are shown? Label them using A, B, . . . . . Time (hours) A B C D Distance (km) Speed (min/km) 8. What is the average speed for the entire trip? How does the value compare to your calculations above? 9. Can you predict how far Michelle will travel if she travels for another 2 hours? Why or why not? What additional information do you need? 7. Calculate the speeds for the different segments of the journey (Hint - you will have to use change in distance!)

18. 5.Describe the motion shown in the graph (moving at varying speed) 6.How many different rates are shown? Label them using A, B, . . . . . Time (hours) A (1 h) B (1h) C (2 h) D (1h) Distance (km) 10 40 10 Speed (km/h) 10 20 10 8. What is the average speed for the entire trip? How does the value compare to your calculations above? 11.7 or 12 km/h 9. Can you predict how far Michelle will travel if she travels for another 2 hours? Why or why not? What additional information do you need? 7. Calculate the speeds for the different segments of the journey (Hint - you will have to use change in distance!)