Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

zello

  • 2 years ago

Kevin can jog to work in 7/12 of an hour. When he rides his bike, it takes him 1/6 of an hour. If he rides 12 miles per hour faster than he jogs, how far away is his work?

  • This Question is Closed
  1. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    It's the same idea as before. The distance to work doesn't change.

  2. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Remember the formula \(d = vt\).

  3. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Since \(d\) is the same no matter how he gets there, \((vt)_{jog} = (vt)_{bike}\).

  4. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    but I don't know why in sometimes it becomes d1+d2

  5. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    All I can think for that would be \(d_{1} + d_{2} = d_{total}\)

  6. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    But that formula wouldn't apply for this question.

  7. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[vt 1=vt2\] \[\frac{ 1 }{ 7 }t=\frac{ 1 }{ 6 } (12-t) \]

  8. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ?

  9. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Once you've determined what to equate (in this case, \(d\)), it's best to write out everything you need and see what you already know. That way, you know what to solve for. You're looking for \((vt)_{jog} = (vt)_{bike}\). There are 4 variables there: \[\begin{align*} v_{jog} &= \\ v_{bike} &= \\t_{jog} &= \\t_{bike} &= \end{align*}\]

  10. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So V for both will be 12 ?

  11. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    You've used \(12 - t\), which is not correct because the 12 relates to his velocity, not time. Go back to your question and see what you can plug in. You should end up with three answers (one will be relative), leaving one variable to solve for.

  12. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    No, V cannot be 12 for both.

  13. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Okay so v bike = 12 and v jop= 12-t

  14. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    No.

  15. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    He doesn't bike at a velocity of 12.

  16. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    he rides 12 miles per hour faster than he jogs

  17. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Yes! There you go.

  18. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    He will ride a bike 12 miles per hour and he will jog 12-t

  19. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Nope. That's the same thing you said before. he does not bike at a speed of 12 mph. He bikes 12 mph *faster* than he jogs. You need to know how fast he jogs to know how fast he bikes.

  20. Chlorophyll
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    " rides 12 miles per hour FASTER THAN" he jogs

  21. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Have you plugged in your values for these? \[\begin{align*} v_{jog} &= \\ v_{bike} &= \\t_{jog} &= \\t_{bike} &= \end{align*}\]

  22. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    nope

  23. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    If he bikes 12 mph faster than he jogs, \(v_{bike} = v_{jog} + 12\), right?

  24. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    That should get you started. There are two more values you can plug in.

  25. Chlorophyll
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @zello then you'd better fill it in, keep in mind the unit match with variable !

  26. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Yes! Keeping track of units is crucial, as is remembering what your variable means when you're done.

  27. Bronco101
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    all i can get is he jogs for 35 minutes, and rides for 10 minutes. He rides 2 miles faster per 10 minutes than he jogs O.O

  28. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    V bike= V jog+12 V jog = V bike-12 T jog =7/12 T bike = 1/6

  29. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Your times are right, but not your velocities.

  30. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    V-jog is wrong.

  31. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    It's just V-jog. Don't equate it to anything. It will be the variable you solve for.

  32. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Okay

  33. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[vt Bike = vt Jog\] \[\frac{ 1 }{ 6 }(vJog+12) =\frac{ 7 }{ 12 } v\]

  34. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Yes! Good.

  35. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    now what ?

  36. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Now solve for \(v_{jog}.\)

  37. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    And remember—the v on the right side is also \(v_{jog}\).

  38. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Call it \(v\), or \(x\), or whatever you want. It's the same no matter how you approach it. If the subscript "jog" confuses you, omit it, but remember what \(v\) represents.

  39. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Ok

  40. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\frac{ 1 }{ 6 }(v+12)=\frac{ 7 }{ 12 }v\] \[\frac{ 1 }{ 6 }v+2=\frac{ 7 }{ 12 }\] \[\frac{ 1 }{ 6}v-\frac{ 7 }{ 12 }v=-2\] \[0.16v-0.58=-2\] \[-0.42 v=-2\] \[v=4.76\]

  41. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    I left my answers in fractions, so I'm not sure. What do you get for your final answer?

  42. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I just solve V jog

  43. Chlorophyll
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @zello something isn't right with your calculation !

  44. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    No, that's not what the question wants. Go back and read the last sentence.

  45. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    @Chlorophyll It's just rounding error. I got \(v_{jog} = \frac{24}{5}\), so I think he's okay.

  46. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Although I only looked at his answer, not his work.

  47. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I'm a girl -_-

  48. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Oh, I'm sorry. I judge too quickly by avatars.

  49. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Although that's obviously not you... :S

  50. Chlorophyll
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Yes, it's very neat V = 24/5 ( 4.8 mi/hr) @zello Better keep it in fraction form!

  51. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    @zello When you get to this stage: \[\frac{ 1 }{ 6}v-\frac{ 7 }{ 12 }v=-2\] Multiply everything by 12 and simplify to get rid of the fractions.

  52. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I have a headache because from 9 A.M until now, I still working on my math >.<

  53. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Well, you've been working hard, and definitely showing growth. You're welcome to take a break, but you're almost done this question. Remember, we needed to find \(v_{jog}\) to solve the equation, but \(v_{jog}\) is not what the question asks for. It asks how far away his work is.

  54. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    how can i found the distance then

  55. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    find *

  56. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    You know your distance formula. We've used it a lot.

  57. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    d= vt d jog= d bike

  58. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Top one.

  59. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    vt jog = vt bike

  60. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    No, just \(d = vt\). You know \(v\) now, and you already knew \(t\), so solve for \(d\).

  61. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    d bike = v bike * t bike d= 4.76 * 0.58 d= 2.7608

  62. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Good. Don't forget your units. It's technically 2.8, so you're a bit off due to rounding errors, but that's right.

  63. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Excellent job working through this.

  64. Chlorophyll
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @zello I wonder if you know how to say thanks by distributing the medal (?)

  65. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thank you so much and I'm sorry that I took a lot of your time. I really appreciate that

  66. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I got 2.8 exactly with my methods.

  67. geoffb
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Not a problem at all. Glad I could help. Thank you for making the effort to solve it on your own and learn.

  68. Chlorophyll
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Yup, that's why I say zello's calculation is incorrect!

  69. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    It' not incorrect, it's just because I didn't round my answer

  70. Chlorophyll
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    It's exact, so there's no need to round!

  71. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    it's not exact in my calculator

  72. Chlorophyll
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    So you're unable to calculate the fraction?

  73. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I know how to calculate the fraction but the question says that they want the answer rounded to the nearest tenth

  74. Chlorophyll
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    First, you should keep the number in fraction if it isn't exact result Second, in this case it's exact! 7v / 12 = ( v + 12 ) /6 (7/ 12 - 1/6)v = 2 -> v = 2 * 12/5 = 24/5 = 2.8 mi/ hr

  75. Chlorophyll
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    There's nothing to round off :)

  76. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    when I calculate it, I didn't use the fraction

  77. zello
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    However, thank you

  78. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Ask a Question
Find more explanations on OpenStudy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.