Writing a physics explanation from scratch:
First, solve the problem.
Before you can explain the solution, you must know how to get to the solution. Therefore, you must demonstrate the steps in getting the answer. You must show correct math steps, accurate graphs, and accurate measurement units.
Second, reflect on the concepts underlying what you have done.
You will be required to explain what you have done. This does not mean simply restating your steps in words. Describe it like you are teaching a child who has never taken physics. This means you will be describe what the equations really mean. You will describe what the numbers actually tell about the physical situation you are investigating. You will be explaining the connection between the various quantities, or graph shapes, or diagrams representing the physical setup.
A well-written physics explanation must answer the following questions in narrative form:
... how the graphs accurately describe the motion, or forces, or energy transfer, or other relevant characteristic of the problem.
... why the equation(s) used in your solution best describe the relationships among the physics quantities you are using.
... why the numbers used in the equations best show the solution to the answer.
... how the numerical answer demonstrates the correct reasoning.
... why the equation(s) used in your solution best describe the relationships among the physics quantities you are using.
... why the numbers used in the equations best show the solution to the answer.
... how the numerical answer demonstrates the correct reasoning.