101 Written Homework Format For your written homework, your quizzes, and the free response questions on your tests, what we grade is the quality of your explanation; having the correct answer is generally worth about 10% of the available points. Your explanations must be presented in the following format; this format is REQUIRED for every written HW, QUIZ, and free-response TEST question. Step 1: MAKE A LIST of your selected variables in the upper left-hand part of your page. For each variable, you must include an assigned symbol, a short written description, and a value (if known) with proper units, or a question mark if the value is unknown. Step 2: In the upper right-hand part of your page, draw an appropriate sketch for the problem. Label relevant objects, arrows, etc. in your sketch with their appropriate symbols and values. Step 3: Below your sketch, explain clearly, in words, your strategy and reasoning for solving this problem. What physical principle is relevant, if any? How does that physical principle relate to the objects, motions, forces, etc. in the problem? Step 4: Below your strategy and reasoning, express the relevant physical principle with an algebraic equation in the symbols you have defined for your variables. ISOLATE THE UNKNOWN VARIABLE ON THE LEFT-HAND SIDE OF THE EQUATION BEFORE MAKING ANY NUMERICAL SUBSTITUTIONS. This may require a small amount of algebra; show your steps carefully. Step 5: BEFORE SUBSTITUTING ANY VALUES INTO YOUR EQUATION, do any necessary unit conversions (for example, you might need to convert km/hour into m/s). Very simple conversions (such as cm into m) can be done as a part of Step 1. Step 6: Substitute the number value AND UNIT for each symbol in the algebraic equation. UNITS ARE REQUIRED AT EVERY STEP. You cannot simply write in the unit beside your final answer; if you do you will receive very little credit. Step 7: Do the indicated mathematical operations on the number AND ON THE UNITS to get your result for the unknown with units. Step 8: Check the reasonableness of your answer. For example, if the unknown was the speed of a human runner, an answer of 100 m/s or more would not be reasonable. If your answer is not reasonable, go back and check your work. Wildly unreasonable answers will be graded harshly. Step 9: Draw a box around your answer to indicate that you have finished this part of the problem. Step 10: If a problem has multiple parts, a second sketch may not be required. Any variables listed in an earlier part do not need to be listed again for the second part. List any new variables needed for the new part, draw a new sketch if necessary, explain your strategy, etc.