---

What principles, laws, or concepts apply to this type of problem ?
Examples:
    Is energy conserved in this problem ?
    Does this problem involve vectors ?
    Are Newton's laws of motion relevant to this problem ? If so, which one ?

---

What do I need to know about this principle, law, or concept in order to figure out how to obtain an equation(s) that relates the unknowns to the knowns ?
Examples:
    If this problem involves the conservation of moment, do I need to review or investigate that principle more before I attack this problem ?
    If this problem involves vectors, do I know how to manipulate vectors well enough to solve this problem ? If I get stuck maybe the concept of vectors is an area that I should review.
    How have I applied this principle or law to problems in the past ? If I have never applied this principle before, maybe I should look at an example problem to see how the principle is applied, or maybe I should study the topic first.

---

What specific conditions are stated or implied about the quantities involved in this type of problem ?
Examples:
    If there is a force involved, is that force constant or variable ? In which direction and on what object is it acting ?
    Are frictional forces important in this problem ?
    Is the object moving at a constant speed or a constant acceleration ?

---

To which object (or group of objects) will I apply the laws of physics that are relevant ? Equivalently, what system shall I choose to focus my attention upon ?
Examples:
     If two blocks are connected by a rope, to which block shall I apply Newton's Second Law ? The first block or the second block, or maybe I should consider both blocks together as a single system. What about the rope, is that a system I should also consider ?

---

What generic equation (or set of equations) goes with the principle or law that is relevant to this problem?
Examples:
    If the net force on a body is stated to be constant, then its accelerations must also be constant, and therefore the kinematic equations for constant acceleration must apply to the body in this problem.

---

Actions:
- Pick out a body to be the center of focus and concentrate on writing down the formulas as they apply to that body. Repeat this process if there are more than two objects involved.

- It is also possible to select a compound body to which a principle can be applied. The laws of physics work equally as well for a system of objects as they do for a single object.

- Express the principles, laws, or concepts as mathematical equations using the labels you selected for the knowns and unknowns.
Examples:
    v_f = a_car t + v_o,   F_net = mg - F_drag,   PE_top = KE_bottom

---

Comments:
- There must be at least as many equations as there are unknowns. If you don't have enough equations then maybe there is some additional principle that you have overlooked.

- When studying an example problem focus on how the principle is applied to the question to generate a formula that solves the problem, and not on the specific steps. There are many ways to generate a final formula that will work.

- Do not expect the equations you generate (that apply to a specific problem) to look like the generic equations found in a textbook. Only in the simplest problems will the equations look the same.

- Even for similar type of problems that employs the same physics principle, the final solution-equation, the bottom line equation, may not look the same. Do not be misled into believing that the bottom line equation you used the last time you solved a problem of this type will be the same this time. What will be the same is the starting principle.

- Given your frame of reference and your personal labels, the resulting equations you come up with may look completely different from that of another student's equations. Both could be equally correct!

---