1. Introduction to Physics

2. What is physics?  Physics is a branch of science that involves the study of the physical world: energy, matter, and how they are related.  In physics, we use mathematics in many ways to explain how matter and energy are related.

3. Problem Solving  The process of solving the problem is more important than the answer.  Therefore showing work in necessary in all cases.

4. Read and analyze the problem.  Identify all the known and the unknowns.  Use the units as hints.  The potential difference, or voltage, across a circuit equals the current multiplied by the resistance in the circuit. That is, V (volts) = I (amperes) × R (ohms). What is the resistance of a lightbulb that has a 0.75 amperes current when plugged into a 120-volt outlet?

5. Knowns and Unknowns  0.75 amperes= I  120 Volts= V  What are you trying to find? = Resistance

6. Write the base equation.  V = I x R

7. Substitute the values in the equation.  V = I x R  120 = 0.75 x R

8. Solve the equation.

9. Evaluate the answer.  Are the units correct?  Is the answer reasonable?