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Homework Help: Finding the rate with T=1/r ln (rR/C + 1) ?

  1. Jan 14, 2009 #1
    I am completely at a loss with this question :confused:

    If one assumes that the current growth rate of consumption remains constant, the then expiration time in years is give by: T=1/r ln (rR/C + 1) where C = current consumption, r = current growth rate of consumption, and R = resource size. Suppose that the world's consumption of oil is growing at the rate of 7% per year (r = 0.07) and the current consumption is approximately 17 X 10^9 barrels per year. Fins the expiration time for the following estimates of R

    a. R ≈ 1691 X 10^9 barrels (estimate of remaining crude oil)

    b. R ≈ 1881 X 10^9 barrels (estimate of remaining crude plus shale oil)
  2. jcsd
  3. Jan 15, 2009 #2
    You're being asked to find T, given an equation and values for r, R and C to substitute in. Assuming the units agree (they are not specified in the definitions of C, r and R), this is just a straight calculation!
  4. Jan 15, 2009 #3
    Alright I followed along and did a straight calculation heres what I got:

    a. T=1/.07 x ln(.07(1691 x 10^9)/17 x 10^9)

    T=1/.07 x ln(6.9876) which = T ≈ 27.7735

    b.a. T=1/.07 x ln(.07(1881 x 10^9)/17 x 10^9)

    T=1/.07 x ln(7.7453) which = T ≈ 29.2441

    Does this seem right?
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