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-   -   Jogger jogs around a circular track with a diameter of 880 meters in 40 minutes (https://www.askmehelpdesk.com/showthread.php?t=504047)

  • Sep 2, 2010, 01:37 AM
    Unknown008

    You are used to the British system?

    Ok, let's change this.

    Um... My computer is besides me. I am 2400 miles away from you. How far is my computer from you?
  • Sep 2, 2010, 01:40 AM
    ashlayy101
    2.2?
  • Sep 2, 2010, 01:43 AM
    Unknown008

    Don't you think that it's 2400 miles away from you? Do you get it or, do you still have something somewhere you're not sure about?
  • Sep 2, 2010, 01:48 AM
    ashlayy101

    I just completely don't get it. All the book really says is to change km to m? I don't know how to do that and when I answer the question I have to put in Type in scientific notation, 4 x 1013 would be typed in as 4e13 like this? Well I don't how to get the answer from 8.86 X 10e10
  • Sep 2, 2010, 01:51 AM
    Unknown008

    In fact the answer is .

    Let's take a smaller distance. You are in your house. The market is 10 yards away from your house. How far are you from the market, in yards?
  • Sep 2, 2010, 01:56 AM
    ashlayy101

    I know every 1 yard is 3 feet so 10 x 3=30ft
    so if you want yards wouldn't it be 10?
  • Sep 2, 2010, 01:59 AM
    Unknown008

    Right! But you didn't have to calculate anything here! The answer was already given to you! Do you see now? :)
  • Sep 2, 2010, 02:03 AM
    ashlayy101

    Yes! So for "A" I did multiply 10 X 8.86 = 88.6 now the total answer is 88.6e12... I just honestly don't know how 12 is even in there or how I got it because I just figured 10e10 so I just started putting numbers down till I got the right answer
  • Sep 2, 2010, 02:08 AM
    Unknown008

    Ok, now to the question.

    The distance of the probe is 8.86e10 km from the Earth.

    Recall that 1 km = 1000 m.

    So, in metres, 8.86e10 km = 8.86e10 x 1000 = 8.86e13 m

    This is using scientific notation. It's just like:



    Now, we come to the time it takes. Can you find it?



    So,

  • Sep 2, 2010, 02:16 AM
    ashlayy101

    So would I set up this problem like this time taken=88.6/3.00=29.5
    or time take=88.6/1000
  • Sep 2, 2010, 02:22 AM
    Unknown008



    So, we have:



    You need to put everything in the number.

    Maybe the scientific notation is not clear...





    Getting back,



  • Sep 2, 2010, 02:31 AM
    ashlayy101

    Im sorry, I still don't get it. I am sorry if I am frustrating you =/
  • Sep 2, 2010, 02:34 AM
    Unknown008

    It's okay. It's just that I am thinking about how to go and make you understand... maybe this way...

    Find:
    I) 2 x 10 = ?
    ii) 58 x 100 = ?
    iii) 6.5 x 10000 = ?
    iv) 3 x 10e2 = ?
  • Sep 2, 2010, 02:42 AM
    ashlayy101
    20
    5800
    65000
    300
  • Sep 2, 2010, 02:43 AM
    Unknown008

    For the last one, no.

    3 x 10e2 = 3 x 10 x 100 = 3000

    okay?

    If this was: 3 x 1e2, then this becomes 3 x 1 x 100 = 300
  • Sep 2, 2010, 02:47 AM
    ashlayy101

    OK
  • Sep 2, 2010, 02:48 AM
    Unknown008

    Ok, now this one:

    3e5 x 6e2 = ?
  • Sep 2, 2010, 02:59 AM
    ashlayy101

    300,000 x 600= 180,000,000
  • Sep 2, 2010, 03:04 AM
    Unknown008

    Correct. Now, you'll see something too.

    180,000,000 in scientific notation is 1.8 x 10^8 , or 1.8e8

    What happened?

    3e5 x 6e2 = (3 x 6) x e(5 + 2) = 18e7

    Now, this is 18 x 10^7 right?

    or

    (1.8 x 10) x 10^7

    This becomes 1.8 x 10^8

    Try these now, using this new way of multiplying numbers, giving your answer in scientific notation.

    1e16 x 8e18 = ?

    5e12 x 3e8 = ?

    9e7 x 7e6 = ?
  • Sep 2, 2010, 03:13 AM
    ashlayy101

    I am starting to understand so would I use these tools to figure out "B"

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