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Section 6.5 Problem Solving

Newton's laws help you figure out acceleration that accompanies forces. This is obvious from the formal statement of the second law of motion of a system of fixed mass.

\begin{equation*} \vec F_{\text{net}} = m \vec a. \end{equation*}

Therefore, all applications of Newton's laws require you to identify forces on the body so that you can sum them to get the net force. Once you have identified the forces, setting up one or more equations of motion involves thinking about the situation analytically. Often, these analytic steps can be broken into the following well-defined steps.

  1. Identify the system.
  2. Identify and list the forces on the system.
  3. Choose a coordinate system.
  4. Generate equations of motion.
  5. Solve for the desired quantities.
  6. Interpret the result.

Some of these steps are implicit in calculations. But, it's always a good idea to identify them explicitly when you are practicing problem-solving. I will present a number of example problems in the following sections. You should go through them, checking your answer with the solution provided.