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Homework Help: Momentum Question

  1. Dec 3, 2009 #1
    1. The problem statement, all variables and given/known data
    1. A 5kg object has a momentum of 15 kg m/s. What is the net force required to accelerate the object to 8 m/s over 15 seconds?
    A) .35N
    B) 1.7N
    C) 5.1 N
    D) 11 N
    E) 23 N

    2. Relevant equations

    3. The attempt at a solution
    So I use that formula (which I am not sure is right). so wouldn't it be mv/t. So, (5)(8)/15 which is 2.67N which is not an answer choice.

    I think I am using the wrong formula, but it's all I can think of! Please help.
  2. jcsd
  3. Dec 3, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    The acceleration is not v/t in this case. The object has initial velocity because its momentum is 15 kg m/s before it starts accelerating.
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