Basic Skills in Physics

Key Physics Terms

• Physics: Study of the physical world.  Science of energy
  
• Metric System: System of measurement based on multiples of 10.
  
• SI System: Systeme International d’Unites (Internation system of units).
  
• Uncertainty: The last digit in a measurement is uncertain—each person may see it slightly differently when reading the measurement.
  
• Significant Figures: Digits that were actually measured and have physical significance. (Also called “significant digits”)

Metric System

• The metric system uses prefixes to indicate multiples of 10

• The “base unit” is when there’s no prefix.
• To determine the equivalent in “base units”:
  1. Use prefix to determine multiple
  2. Multiply number by the multiple
  3. Write the result with the base unit

• Examples:
• 1.25 mL -->  “milli” means 0.001  -->  0.00125 L
• 87.5 kg   -->  “kilo” means 1000   -->  87500 g

SI System

• The SI sytem gives the fundamental unit for each type of measurement

Measurements & Uncertainty

Significant Figures

Significant figure rules are used so that everyone that reads data or results understands to what precision data was recorded.

Only figures that were actually measured are significant.

Summary of rules for counting significant figures:

1. If there is a decimal point anywhere in the number: Start with the first non-zero number and count all digits until the end.
2. If there is not a decimal point in the number: Start with the first non-zero number and count until the last non-zero number

Examples:

• 10.020 g --> Rule #1 --> 10.020 --> 5 significant figures
• 0.00240 L --> Rule #1 à 0.00240 --> 3 significant figures
• 1250 mL --> Rule #2 à 1250 --> 3 signficant figures
• 10200 mg --> Rule #2 à 10200 --> 3 signficiant figures

Fundamental Constants

Scientific Processes

Although there is not one “scientific method,” there are aspects that are common to scientific investigations:

• Observations
  
• Questioning
  
• Hypothesis formation
  
• Experimentation
  
• Trend recognition
  
• Conclusion formation
  
• Communication and validation of results
  
• Model formation

How to Study Physics

• Memorize basic information to speed up problem-solving later.
• Try to learn vocabulary quickly so you’re familiar with it when you see it.
• Brush up on algebra—don’t try to memorize every variation of an equation!
• Look for commonalities between different problems—many different types of problems are similar than they appear.
• Break each problem down into steps—always identify the given information and where you’re headed.
• Try to understand why behavior occurs & look for pattersns.
• Connect new concepts to previously learned concepts.
• Keep up with the work—don’t let yourself fall behind.
• Ask for help when you need it!