1-1: What is physics?
• Physics is the study of the physical world … light,
motion, energy, electricity, etc.
• Physics uses the scientific method to discover general
laws that can be used.
• Scientific method
1. define the problem
2. gather information
3. form the hypothesis
4. experimentation
5. collect/analyze data
6. state your conclusion
• Areas within physics:
Mechanics – motion and its causes
Thermodynamics – heat and temperature
Vibrations and waves – specific types
of repetitive motions
Optics – light
Electromagnetism – electricity, magnetism,
and light
Relativity – particles moving at any
speed (incl. very high speeds)
Quantum mechanics – behavior of submicroscopic
particles
• Models – used by physicists to explain features of
various phenomena
• Controlled experiment – only one variable is altered
(at a time)
1-2: Measurements in experiments
• Physics uses the metric (SI) system.
• Basic units:
Length – meter
Volume – liter
Mass – kilogram
Time – second
• Know the metric prefixes on Table 1-3 on p. 12
• Accuracy – how close a measurement is to a specified
standard
• Precision – results from the limitations of the measuring
device
• Significant figures – the result in a calculation cannot
have more significant figures than any number used in its calculation;
it insures that results are not more precise than the data used to produce
them
• Rules for Significant figures – see Table 1-4 on p.
17
• Types of investigations - observation, description,
literature survey, classification, or experimentation
1-3: The language of physics
• Using tables/graphs and abbreviating quantities in
equations makes it easier to summarize data.
• Dimensional analysis helps identify if a physics expression
is valid.
• Using order-of-magnitude calculations provides a quick
way to see if your answer is in the ballpark. |
