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Homework Help: Linear Momentum and Collisions- Acceleration Relative to the Ice

  1. Oct 17, 2008 #1
    On a cold winter morning, a child sits on a sled resting on smooth ice. When the 9.10 kg sled is pulled with a horizontal force of 37.0 N, it begins to move with an acceleration of 2.50 m/s^2.The 23.0 kg child accelerates too, but with a smaller acceleration than that of the sled. Thus, the child moves forward relative to the ice, but slides backward relative to the sled.

    Q.Find the acceleration of the child relative to the ice.

    There are several equations that fall under the Linear Momentum and Collision category and none of them seem to quite be relevent enough to the question, obviously this is mostly due to the fact that I dont see the correlation. None of the formulas seem to help me to find an Acceleration, neither does Energy Conservation( which is what I was thinking would help in this problem) help me to find Acceleration.

    I am a little confused as to how to go about this problem as I am unable to see which way to even start, or what I should be using to get to the end result, the Acceleration of the child relative to the ice.

    Any help or guidance would be much appreciated.
  2. jcsd
  3. Oct 17, 2008 #2
    The best way to start almost any physics problem is to draw a picture of the problem and then to make a Free Body Diagram of each component. Think about each force that might be present and think about what the sum of all forces will be. See if your diagrams give you any ideas.
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