1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Time derivatives

  1. Mar 9, 2012 #1
    1. The problem statement, all variables and given/known data

    My question is how do I take the time derivative of (theta dot)^2?


    2. Relevant equations



    3. The attempt at a solution

    Is the answer just 2(theta double dot)^1 or do you use chain rule 2(theta dot)*(theta double dot)?
     
  2. jcsd
  3. Mar 9, 2012 #2
    Well, assuming theta is a function of time, you must use the chain rule!
     
  4. Mar 9, 2012 #3

    HallsofIvy

    User Avatar
    Science Advisor

    I take that your "dot" refers to differentiation with respect to time, t,- I will use a prime since it is simpler here- and you are asking about the derivative of [itex](\theta')^2[/itex].

    The derivative of any [itex](f(t))^2[/itex] with respect to t is [itex]2f(t)f'(t)[/itex], by the chain rule, so the derivative of [itex](\theta(t)')^2[/itex] is [itex]2(\theta')(\theta'')[/itex].
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook




Loading...