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Homework Help: Force Problem

  1. Apr 14, 2010 #1
    1. The problem statement, all variables and given/known data
    Mike is dragging a 20.0 kg crate across the floor. If he exerts 40 N force upon the crate and there is a 25 N frictional force opposing the crate's motion, how fast will the crate be moving after 2.0 seconds if it is initially at rest?

    2. Relevant equations

    3. The attempt at a solution
    I used FNET=ma to solve for the acceleration as follows:

    Then here's where I'm not sure if this is correct: I multiplied the acceleration 0.75m/s2 by 2.0 seconds to get 1.5m/s2.
    Is this the correct answer for the question: How fast will the crate be moving after 2.0 seconds?
  2. jcsd
  3. Apr 14, 2010 #2
    Almost right. What happens when you multiply an acceleration by a time? What are the units? (You have the correct numeric answer, your units are off)
  4. Apr 14, 2010 #3
    Oh it wouldn't be squared. So it would be 1.5m/s.
  5. Apr 14, 2010 #4
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