Physics Chapter 1 Test
What is Physics
-Physics uses the scientific method to discover general laws that can be used to make predictions about a variety of situations. -A common technique in physics for analyzing a complex situation is to disregard irrelevant factors and create a model that describes the essence of a system or situation
The scientific method
1.Make observations and collect data that lead to a question 2.Formulate and objectively test hypotheses by experiments 3.interpret results, and revise the hypothesis if necessary 4.State conclusions in a form that can be evaluated by others
A room is measured to be 3.6 m by 5.8 m. What is the area of the room?
21 m(squared)
A light-year (ly) is a unit of distance defined as the distance light travels in one year. Numerically, 1 ly= 9 500 000 000 000 km. How many meters are in a light-year?
9.5×10^15m
Relativity
particles moving at any speed, including very high speeds ex)particle collisions, particle accelerators, nuclear energy
10^15
peta- P
10^-12
pico- p
Difference between accuracy and precision
Accuracy-describes how close a measurement is to reality. Precision-results from the limitations of the measuring device used
What area of physics deals with the behavior of subatomic particles?
quantum mechanics
Which of the following statements is true of any valid physical equation?
Both sides have the same dimensions
Vibrations and wave phenomena
specific types of repetitive motions ex)springs, pendulums, sound
What term describes a set of particles or interacting components considered to be a distinct physical entity for the purpose of study?
system
10^12
tera- T
What is physics the study of
Physics is the study of the physical world, from motion and energy to light and electricity
Physics measurements are typically made and expressed in
SI, a system that uses a set of base units and prefixes to describe measurements of physical quantities
Quantity-mass
Symbol-m Units-kilograms abbreviations-kg
Quantity-time interval
Symbol-Δt Units-seconds abbreviations-s
Quantity- change in vertical position
Symbol-Δy Units-meters abbreviations-m
If you do not keep your line of sight directly over a length measurement, how will your measurement most likely be affected?
Your measurement will be less accurate
accuracy
a description of how close a measurement is to the correct or accepted value of the quantity measured
Model
a pattern, plan, representation, or description designed to show the structure or workings of an object, system, or concept
Order-of-magnitude calculations provide
a quick way to evaluate the appropriateness of an answer
System
a set of particles or interacting components considered to be a distinct physical entity for the purpose of study
significant figures of a measurement include
all of the digits that are actually measured plus one estimated digit
controlled experiment
an experiment that tests only one factor at a time by using a comparison of a control group with an experimental group
hypothesis
an explanation that is based on prior scientific research or observations and that can be tested
10^-18
atto- a
Quantum mechanics
behavior of submicroscopic particles ex) atom and its parts
10^-2
centi- c
10^-1
deci- d
Significant-figure rules provide a means to ensure that calculations
do not report results that are more precise than the data used to make them
Electromagnetism
electricity, magnetism and light ex)electrical charge, circuitry, permanent magnets, electromagnets
10^-15
emto- f
10^18
exa- E
10^9
giga- G
precision
he degree of exactness of a measurement
Thermodynamics
heat and temperature ex)melting and freezing processes, engines,refrigerators
10^3
kilo- k
Optics
light ex)mirrors, lenses, color, astronomy
10^6
mega- M
What is the SI base unit for length?
meter
10^-6
micro-μ(Greek letter mu)
10^-3
milli- m
Mechanics
motion and its causes, interactions between objects ex) falling objects, friction, weight, spinning objects
10^-9
nano- n
What technique can help you determine the power of 10 closest to the actual numerical value of a quantity?
order-of-magnitude estimation
What area of physics deals with the subjects of heat and temperature?
thermodynamics
significant figures
those digits in a measurement that are known with certainty plus the first digit that is uncertain
Dimensional analysis can help identify
whether a physics equation is invalid