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Homework Help: This problem has to do with mass and time

  1. Aug 24, 2008 #1
    1. The problem statement, all variables and given/known data
    Water is poured into a container that has a leak. The mass m of the water is given as a function of time t by m=5.00(t)^.8- 3.00t+ 20.00. with t being greater or equal to zero, m in grams, and t in seconds. (a) at what time is the water mass greatest (b) what is the greatest mass? in kilograms per minute, what is the rate of change at (c) t=2.00 s and (d) t=5.00s

    how do i do this probelm

    2. Relevant equations
    what equations can i use

    3. The attempt at a solution

    if i knew what to do or sort of do i could attempt it
  2. jcsd
  3. Aug 24, 2008 #2
    is question a asking me to plug in a time that will allow the equation to equal to zero
  4. Aug 24, 2008 #3


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    Homework Helper

    This is a problem in optimisation using calculus. Think of how to find the max and min of a function. That's all you need to do this problem, no physics involved.
  5. Aug 25, 2008 #4
    I figured it out. It was 4 seconds for question (a) and that opened up the rest of the problems.
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