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Homework Help: Using hookes law to find impulse

  1. Dec 10, 2011 #1
    1. The problem statement, all variables and given/known data
    You are given a FORCE versus TIME graph, which shows oscillations with:

    A= 4N at the max points
    period is 4s
    spring constant (k)= 12.3 N/m
    mass of block exhibiting oscillation is 4.9 kg


    How do you find the IMPULSE delivered to the block during the 1st 2 seconds of oscillation?

    2. Relevant equations:
    impulse=Δp
    E=kx
    x(t)= Acos(wt)
    w=2∏f
    W=deltaEk or F(D)



    3. The attempt at a solution
    x(t)=Acos(wt)

    x(0)=4cos0=4N
    x(2)=4N

    I don't know how to connect this information
     
  2. jcsd
  3. Dec 10, 2011 #2

    Delphi51

    User Avatar
    Homework Helper

    Welcome to PF, Captain!
    Do you have the graph? It depends where it starts - is F=0 at time zero or what?
    The usual impulse formula is F*Δt. Your F varies with time; can you integrate F*dt over the Δt?
     
  4. Dec 10, 2011 #3
    Find the function F that defines force (it is a sine or cosine, from what you told). Integrate it over the time interval from 0 to 2 seconds.
     
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