## anonymous one year ago You drive a car 2.0 km to the gas station, 4.0 km to the shopping mall to let your mother off, and 4.5 km back home. The trip takes 20.0 min. What is your average speed? 3.2 m/s 4.38 m/s 8.75 m/s 0.525 m/s

1. anonymous

@Learner11

2. anonymous

@Nnesha

3. anonymous

@phi

4. sophiaholder

OKay so, S = distance/time

5. sophiaholder

So, you would want to add up how many kilometers you traveled first.

6. anonymous

that would be 10.5/20.00 right?

7. sophiaholder

Nope. If we are trying to find miles/seconds we need to convert them

8. DanJS

<Speed> = ....

9. anonymous

oh

10. DanJS

Do you remember calculating the 'average rate of change' given two points on a graph from algebra

11. DanJS

slope of a secant line connecting the two points on the graph...

12. sophiaholder

Dan can probably explain this better than me, so I leave this one to him

13. anonymous

I have no Idea what your talking about my brain just died

14. DanJS

It is the same as that, except it is a graph of (Total distance traveled) vs (total time traveled) for the y and x axis

15. DanJS

To get the average speed - you take the initial value point (0 min, 0 km) and the final point (20 min , (4.5+2.0+4.0) km ) and calculate the slope of the line through those

16. DanJS

In short, the average speed on an interval will be the ratio of the total distance traveled over the total time traveled

17. anonymous

@dan815

18. DanJS

$ave~speed = \frac{ distance ~traveled }{ time of traveling }$

19. DanJS

you will get km/min need to convert to m/s

20. anonymous

O.o

21. dan815
22. dan815

convert it into meters/second

23. anonymous

I DON'T UNDERSTAND x-x

24. DanJS

$\frac{ X~km }{ 1~\min }*\frac{ 10^3~m }{ 1~km }*\frac{ 1~\min }{ 60~s } = \frac{ X * 10^3 }{ 60 }*\frac{ m }{ s }$

25. anonymous

omg

26. dan815

okay do you get that speed = d/t

27. anonymous

distance divided by time?

28. dan815

yes speed tells you the rate of distance change over time

29. dan815

you saw that 10.5 km traveled in 20 mins right

30. dan815

tell me if that part is clear or not, gotta know this to move on

31. dan815

10.5 = 2+4+4.5

32. anonymous

Everything

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