When first solving a problem, our initial concern should not
be with specific numbers and calculations, but with simply understanding the
information in a useful way.
The Pictorial Model is a good way to do this.
A Pictorial Model should include:
- A sketch of the situation, showing each object
- at the beginning of the motion,
- the end of the motion,
- and at any point in between where the character of
the motion changes.
- A coordinate system that you impose on the problem, including
a choice of th origin, the axes, and the positive direction.
- Symbols, on the sketch, to show position, velocity, and
time with subscripts for each time an object is shown on your sketch. Also,
show symbols for other relevant quantities such as mass
- Arrow indicating the direction of the acceleration vector
or vectors. Write
a = 0 if the acceleration is zero.
- A Table listing the values for all quantities given in
the problem or that can be found quickly using geometry.
- A list of the unknown quantities you have been asked to