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Homework Help: Sig Figs and Conversion

  1. Dec 5, 2008 #1
    Hey I dont want to loose points for this primary question, could someone please go over my answers. Thanks!

    1. The problem statement, all variables and given/known data


    1. Perform the following operations and write your answers with appropriate
    number of significant figures: (a) 589.01−89.020 (b) 1.0×9.00 (c) 180 /pi
    (d) 180.0 /pi (e)3.901x10-5+ 1.0x10-7

    2. Perform the following unit conversions and express the answer in scientific
    notation: (a) 0.510 kg to g (b) 92 mi to km (c) 3 0.50 m to 3 cm (d) 15 μs to ms
    (e) 60.0 km/h to m/s




    3. The attempt at a solution

    a) 589.01-89.020 = 499.99
    b) 1.0 x 9.00 = 9.0
    c) 180/ Π = 57
    d) 180.0/Π = 57.30
    e) 3.901 x 10^-5 + 1.0 x 10^-7 = 0.00004


    2. a) 0.510kg x 1000g/1kg= 5.1 x 102g

    b) 92 mi x 1.609344km/1mi= 1.48059 x 102 km

    c) 0.50m3 x 1 000 000cm3/ 1m3 = 5 x 105 cm3

    d) 15μs x 1ms/0.001 μs = 1.5 x 10-2ms

    e) 60.0km/1hour = 65000m/3600 sec = 1.805556 x 101 m/s
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Dec 5, 2008 #2
    1e looks reeaall suspicious.

    If I multiplied both numbers by 10^7 (for my convenience), I'd see 390.1 + 1.0

    I don't have to convert it back to the proper decimal place to see there's a problem with saying 400
     
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