Present your work so that the grader knows what you are
thinking.
Just giving “the answer” to a problem without any work will
earn you no credit, even if you are correct.
Style
Your problem solution should be written in technical style.
When helpful, present information in the form of idealized
diagrams, tables, lists, mathematical derivations, and so forth.
Solution Structure
Diagram
Begin your solution by presenting the situation it describes
and all of the information it gives you, i.e., by presenting your understanding
of the problem definition. Drawing a picture is usually the most effective (and
time efficient — very important on exams) way to do this; incorporate the given
information into the picture by labeling it. Turn your picture into a technical
diagram reducing the situation to only the physically relevant parts. For
example, if our problem were about forces, draw a free-body diagram.
Given and target data
Describe the Physics. Convert the problem that you have described into physics
terms.
Define physical variables. Write down given data and target quantity, using variable
symbols.
Equations
Write down related equations that you think will be useful. Concretely, it often helps to classify your problem by its method of solution.
Math
Use mathematics to find a symbolic expression giving the
target quantity in the terms of the given information.
I don’t ask you to provide textual commentary as you go,
narrating what you are doing and explaining anything, as often it is very
difficult to read hand-written texts, however you should write out all your
steps of mathematical transformations in correct mathematical expressions.
Use logical symbols or short phrases (one - two words) to
explain the sequence and the logic of your work. Make your logic clear.
You should use the conventions of physics and mathematics to
communicate much information implicitly.
For example, don't explain that g is the acceleration due to
gravity, because it is conventional and because of the context.
Solve with symbols first. Do not substitute numerical values
into your expressions as you go. Work with symbols.
Substitution
When you have your symbolic solution giving the target
quantity in the terms of the given information (expressed by symbols), you can
substitute any given (or generally known ones, like g) numerical values with
appropriate measurement units into your symbolic solution to find a numerical
solution with measurement units.
Show transformations with measurement units. Give prove that
your symbolic solution give correct units of the target quantity.
This part will not be present for problems that don’t provide
numerical values.
Report
Write separately and highlight final numerical value. Report
numbers with units specified and with reasonable significant figures.
Main Sections
So, main sections of your solution:
1. Diagram
2. Given and target data
3. Equations
4. Math (Math transformations to find a symbolic solution)
5. Substitution (Substitutions of numerical physical values
into the symbolic solution)
6. Report
6. Report
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