## anonymous one year ago The graph below shows the distances, in miles, that a dragonfly can travel in a certain number of hours: A graph titled Motion of a Dragonfly shows Time in hours on the x axis and Distance in miles on the y axis. The scale on the x axis shows number from 0 to 10 at increments of 2 and on the y axis the numbers are shown from 0 to 250 at increments of 50. A straight line joins the ordered pairs 0, 0 and 2, 50 and 4, 100 and 6, 150 Based on the graph, what is the dependent variable, the equation relating the two variables, and how far will the dragonfly travel in 24 hours if it continues t

1. anonymous

The dependent variable is distance, the equation is y = 25x, and the dragonfly will travel 600 miles. The dependent variable is distance, the equation is x = 25y, and the dragonfly will travel 720 miles. The dependent variable is time, the equation is y = 25x, and the dragonfly will travel 600 miles. The dependent variable is time, the equation is x = 25y, and the dragonfly will travel 720 miles.

2. anonymous

@Deeezzzz

3. anonymous

@d3v13

4. anonymous

@mathstudent55

5. anonymous

someone plz help

6. UnkleRhaukus

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7. anonymous

yes

8. UnkleRhaukus

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9. anonymous

correct

10. UnkleRhaukus

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11. anonymous

yes it is

12. UnkleRhaukus

so what is the dependent variable ?

13. anonymous

the y axis

14. UnkleRhaukus

which variable does this correspond to (for the dragonfly)

15. anonymous

what do u mean

16. anonymous

?????

17. UnkleRhaukus

which variable (distance or time)

18. anonymous

distance

19. UnkleRhaukus

yes the 'distance' the dragonfly can fly is the dependent variable, [this distance depends on how how much time the dragon fly has]

20. anonymous

so is the answer either a or c

21. anonymous

nvm its A, right

22. UnkleRhaukus

the slope intercept form of a straight line through the origin, is y = mx + b when the slope of the line is m and the y-intercept is b.

23. anonymous

y=25x right??

24. UnkleRhaukus

we see that the line passes through the origin, so we know that b=0. but what is the slope m?

25. anonymous

is it a

26. UnkleRhaukus

if we find the slope between (0,0) and (2,50) m = (50-0)/(2-0) = 50/2 = 25 so yes the slope m is 25

27. anonymous

yaaaay thx

28. anonymous

is it a

29. anonymous

????

30. anonymous

y=25x

31. UnkleRhaukus

you have y(x) = 25x or equivalently distance(time[hours])[miles] = 25[miles/hours] * t[hours]

32. anonymous

33. UnkleRhaukus

what do you get when time[hours] = 24[hours] d(24[hr])[mi] = 25[mi/hr] * 24[hr]

34. anonymous

??????????

35. anonymous

just tell me if it is A

36. UnkleRhaukus

multiply 25 [miles/hour], by 24[hours]

37. anonymous

600

38. anonymous

so a is correct

39. UnkleRhaukus

[units?]

40. anonymous

i did 25 x 24

41. UsukiDoll

units matter too ....

42. UsukiDoll

25 m/h x 24 h

43. anonymous

so what do i do

44. UsukiDoll

a unit can be canceled out

45. UsukiDoll

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46. anonymous

so A is not right????

47. UnkleRhaukus

$25 [\text{mi}/\text{hr}] \times 24[\text{hr}] =(25\times24)\frac{[\text{mi}][\text{hr}]}{[\text{hr}]} \\ =(25\times24)\frac{[\text{mi}]\cancel{[\text{hr}]}}{\cancel{[\text{hr}]}}$

48. UsukiDoll

Thank you @UnkleRhaukus

49. anonymous

600m

50. UsukiDoll

there we go.

51. anonymous

ohhhh

52. anonymous

so a is right

53. UsukiDoll

bunch of physics problems have numbers and units. so we need to keep the units while we're computing... otherwise the grader will be like 600 what ? 600 miles

54. UnkleRhaukus

meters is [m], miles is [mi] .

55. anonymous

k thx

56. UnkleRhaukus

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