2. Motion Problems 2

3. A man bikes from A to B at 20 km/h. He returns by car at 60 km/h. The bike trip is 2 hours longer than the car trip. How far is it from A to B?

4. Which one?

5. R X T = D Method Bike Car 20 60 x + 2 x The distance is always filled in by multiplying the rate and time. 20(x + 2) 60x Distances are equal.

6. 20x+40 = 60x 20(x+2) = 60x -20x 40 = 40x 40 1 = x

7. A man bikes from A to B at 20 km/h. He returns by car at 60 km/h. The bike trip is 2 hours longer than the car trip. How far is it from A to B?

8. R X T = D Method Bike Car 20 60 x + 2 x 20(x + 2) 60x What does x represent? What represents distance?

9. If x=1, distance is: 60x=6060x=?? 20(x+2)=?? 20(x+2)=60

10. The answer is: 60 km

11. Problem #2 on Worksheet 61

12. Vince bikes for 2 hours at 18 km/h. Then he rides by car for 3 hours. His total distance is 246 km. How fast does the car travel?

13. Which one?

14. None of those. It’s this one: The distances add up to the total distance.

15. R X T = D Method Bike Car 18 x 2 3 The distance is always filled in by multiplying the rate and time. 36 3x3x 246

16. 36+3x = 246 -36 3x = 210 33 x=70 -36

17. R X T = D Method Bike Car 18 x 2 3 36 3x3x 246 What does x represent?

18. Vince bikes for 2 hours at 18 km/h. Then he rides by car for 3 hours. His total distance is 246 km. How fast does the car travel?

19. The answer is: 70 km/h

20. Problem #3 on Worksheet 61

21. Cindy bikes from A to B at 20 km/h. She returns by car at 80 km/h. The bike trip is 3 hours longer than the car trip. How far is it from A to B?

22. Which one?

23. R X T = D Method Bike Car 20 80 x+3 x The distance is always filled in by multiplying the rate and time. 20(x+3) 80x Distances are equal.

24. 20(x+3) = 80x -20x 60 = 60x 60 1=x 20x+60 = 80x -20x

25. R X T = D Method Bike Car 20 80 x+3 x 20(x+3) 80x What does x represent?

26. Cindy bikes from A to B at 20 km/h. She returns by car at 80 km/h. The bike trip is 3 hours longer than the car trip. How far is it from A to B?

27. The answer is: 80x= 80(1)= 80 km

28. Problem #4 on Worksheet 61

29. Judy can bike 2 km/h faster than Linda. They travel in opposite directions for 2 hours. They are then 68 km apart. How fast is each girl traveling?

30. Which one?

31. R X T = D Person Judy Linda x+2 x 2 2 The distance is always filled in by multiplying the rate and time. 2(x+2) 2x2x 68

32. 2(x+2)+2x = 68 -4 2x+4+2x = 68 4x= 64 4x+4 = 68 -4 4 4 x=16

33. R X T = D Person Judy Linda x+2 x 2 2 2(x+2) 2x2x 68 What does x represent?

34. x+2= Judy’s rate of speed x+2= x= 16 km/h 18 km/h x= Linda’s rate of speed

35. THE END