[Prelim] Physics Flashcards
Is an experimental science.
Physics
Observe the phenomena of nature and try to find patterns that relate to these phenomena.
Physicists
Scientific ideas starts as __________ and evidence may or may not support them.
Predictions
Physical Quantities:
Fundamental (or base) Quantities
Derived Quantities
Fundamental Quantities:
- Length
- Mass
- Time
- Temperature
- Electric Current
- Luminous Intensity
- Amount of Substance
Derived Quantities:
- Speed
- Density
- Force
Infromal Ststem of measurement:
- Handspan
- Cubit
- Armspan
- Face
- Foot Span
System of measurement:
- British (imperial) system or imperial system
- Metric or international System (SI)
British Imperial System:
- Length
- Volume
- Mass
- Time and Date
Measurement for the length and distance:
- Meterstick
- Trundle wheel
- Tape measure
- Vernier Caliper
Measurement for Mass:
- Electronic balance
- Double Pan Balance
- Triple Bean Balance
Measurement for Volume:
- Graduated Cylinder
- Volume of Solids
- Volume of irregular solids
Measurement for temperature:
- Thermometer
Measurement Error:
- Random Error
- Systematic Error
- proposed explanation that has been extensively tested and is based on many observations.
- an explanation of why something happens based on years of testing and obervations.
Theory
- a rule that describes how something in nature behaves, but not necessarily why it behaves that way.
- describes what happens under certain conditions.
Law
Require measurements, we generally use numbers to describe the results of measurements.
Experiments
Some physical quantities are so fundamental that we define them only by describing how to measure them.
Operational definition
- only three _____________ were considered; length, mass, time.
- with the developments of science, four more physical quantities were added.
Fundamental (or base) Quantities
The quantities that are derived from the fundamental quantities like speed, acceleration, density, force, and momentum.
Derived Quantities
Defined as distance covered over time.
Speed
Defined as mass per unit volume.
Density
Defined as mass acceleration.
Force
when we measure a quantity, we always compare it with some reference ________.
Standard
The _____ is a unit of distance, and the ______ is a unit of time.
- Meter
- Second
Are a collection of units of measurements and rules relating them to each other.
Measurements Systems
- the international system of units, or SI, is the preferred method of measurement in Physics.
- It has a base unit for every type of measurement.
Metric System or SI
SI stands for _________. French for _______
- Système Internationale
- International System
SI basic unit of Length (distance)
Meter (m)
SI basic unit of mass
Gram (g)
SI basic unit of weight (force)
Newton (N)
SI basic unit of volume (capacity)
Liter (L) or Cubic meter (m3)
SI basic unit of temperature
Kelvin (k)
SI basic unit of time
Seconds (s)
SI basic unit of pressure
Newtons per square meter (N/m2)
SI basic unit of electric Current
Ampere (A)
SI basic unit of amount of substrate
Mole (mol)
The US follows the imperial system of units, also called the U.S customary units.
British Imperial System
The four commonly used measures of ______ are inch, feet, yards, miles.
Length
The most common measures of ______ in the US customary units are fluid ounces (fl. oz), cups, pints, quarts, and gallons.
Volume
The most common measurements of mass in the US customary units are ounces (oz), pounds (Ib), and (ton).
Mass
_____ is still measured in seconds.
Time and Date
- the distance between two points.
- the SI unit for length is meter (m).
Length or distance
- like a ruler, except it is 1 meter long (100cm)
- It is a bit longer than a yardstick.
Meterstick
-to measure long distances, just roll the _________ on the ground, and every time you walk a meter, the _______ makes a dicking sound.
Trundle wheel
for measuring distances that would be hard to measure using a meterstick or a trundle wheel, such as the distance around a round object.
Tape measure
Used for the measurement of diameters of round objects with the help of the measuring jaws.
Vernier Caliper
- the period between events or how long something lasted.
- the SI unit for time is seconds.
- other units for time include hours, days, months, and years.
Time
- the amount of matter in a liquid, solid, or gas.
- SI unit for mass is gram (g)
Mass
Just put the object on the pan and read the mass.
Electronic Balance
- compares the weight of objects in pans on each side of a balance.
- to find mass, place something of known mass in one pan, and in the other pan, place the object of unknown mass.
- when the pans are level, the mass are equal.
Double Pan Balance
- works like a double pan balance, but instead of having a pan on each side of the balance, there is a pan on one side, and three beams, each with siding weights, called RIDERS, on the other.
Triple Beam balance
- the force exerted by a mass.
- SI unit for force is in Newtons (N)
Weight
The amount of space something occupies.
Volume
- a cylinder marked on the outside to indicate how much fluid it contains.
- take your volume reading from the bottom of the Meniscus and make sure you are taking the reading at eye level.
Graduated Cylinder
take your volume reading from the bottom of the ________ and make sure you are taking the reading at eye level.
Meniscus
- to figure out the volume of a rectangular solid, simply measure its height, width, and length using any of the tools for measuring length, and then multiply all three.
Volume of solids
- the best way to measure the volume of an __________ is to place it in water and find the volume of water it displaces.
- the difference between the new and old volume measurements in equal to the volume of the object.
Irregular solid
- how hot or cold something is.
- SI unit for temperature is Kelvin.
- Most scientists use the SI-derived unit, Celsius, to measure temperature.
Temperature
SI unit for temperature is _______.
Kelvin
- used to measure temperature.
- can be digital or liquid.
Thermometer
- there can be sources of error in any type of measurement.
- this means that if you measure a quantity once and then a second time, you may get a different reading.
Measurement Error
Is independent of accuracy
Precision
Is the measure of how close the measured value is to the actual value of the quantity.
Accuracy
- difference between a measured quantity and its true value.
- is includes random error (naturally occurring errors that are to be expected with any experiment) and systematic error (caused by a miscalibrated instrument that affects all measurements).
Measurement error (observational error)
Naturally occurring errors that are to be expected with any experiment.
Random error
- affects the accuracy of a measurement.
- if the instrument that you are using is not properly set, it cannot give an accurate measurement.
- caused by a miscalibrated instrument that affects all measurements.
Systematic error
- reading of an instrument are compared to a known measurement to check its accuracy. AKA “Zerogoins”
Calibration
reading of an instrument are compared to a known measurement to check its accuracy. AKA “________”
Zerogoins
- caused by errors in the experimental apparatus or by the person who is reading the measurement.
- random errors affect the precision of the measurement.
Random Errors
- Difference between a measured value and a known value expressed as a percentage.
- shows how far the experimental value is from the accepted value when comapred with the size of the actual value.
Percent Error
Known to be true and can be found in a standard reference.
Accepted value
The value that you actually measured.
Experimental Value
Estimates how repeated measurements taken on the same instrument are estimated around the score.
Standard error of measurement (SEM)
- measure of the variability of a distribution of repeated scores or measurements.
- smaller values indicate a smaller variation and therefore values closer to the true score.
Coefficient of variation ( CV)
Gives an estimate of the interval where a proportion of the difference lies between measurements.
Limits of agreement (LOA)
Methods to assess absolute reliability:
- Standard error of measurement (SEM)
- Coefficient of variation ( CV)
- Limits of agreement (LOA)
-also called the uncertainty
-it indicates the maximum difference there is likely to be the measured value and the true value.
Error
-the uncertainty is indicated in the measured value.
-the numbers reported in the measurement.
-are all of the known figured plus one estimated digit.
Significant figures
-is called the significant digit.
-scientists reach it by using estimation or by rounding numbers.
Estimated digit
is the number that provides the most exact measurement possible.
Significant digit
rough guess of the measurement using observation and reasoning.
Estimation
picking the closest number to the specified place value based on the accuracy of the equipment.
Rounding
-is a mathematical method used to convert actual measured units into the units needed for the answer to a problem.
Dimensional Analysis
- AKA “ratio”
- the relationship between the two units.
Conversion Factor
Conversion factor is also known as-
Ratio
SI Prefix (in order):
giga (G)
mega (m)
kilo (k)
hecto (h)
deca (da)
Base Unit
deci (d)
centi (c)
milli (u)
nano (n)
