The Force Method

1) Draw a good diagram of the situation.

2) Draw a free-body diagram: Start with a rectangle (which represents the object in question) with a dot at its center and draw the force vectors pointing AWAY FROM the dot. Also draw the acceleration vector (if there is one).

3) Determine the dimensionality of the problem: If all of the vectors point along one straight line, then the problem is one-dimensional. If not, then the problem is two-dimensional.

4) Choose the orientation of the coordinate system such that as many vectors as possible lie directly on one of the axis.

5) Set up the equations: If the acceleration is zero, then use Newton's 1st Law. Otherwise, use Newton's 2nd Law. The number of equations will equal the number of dimensions.

6) Solve the equation(s) for the unknown variable(s).

7) Solve the associated kinematic problem (if there is one).