| Term | Definition |
| physics | the study of the physical world |
| branches of physics | mechanics, thermodynamics, vibration and waves, optics, electricity and magnetism, relativity, and quantum mechanics |
| scientific method of problem solving | state the problem
gather information
form hypothesis
test hypothesis
analyze data
draw a conclusion |
| experiment | procedure for testing hypothesis |
| variable | quantity that can change |
| independent vs. dependent variable | independent variable is the variable that you change and the dependent variable is the one you measure |
| control variable | standard by which results are compared |
| model | idea, system, or structure that represents reality |
| standard | quantity people agree on to use for comparison |
| measurement systems | English system (ft., cup, gallon, etc.)
Metric system ( m., g., Celcius, etc.)
SI system (m., Kg., K, etc.) |
| volume | space occupied by an object |
| length | distance between two points |
| mass | amount of matter in an object
measured in g, Kg, cg, mg, etc. (SI unit=Kg) |
| density | mass per unit volume
measured in g/cm^3, g/mL, kg/m^3, ect |
| temperature | SI unit=K
0 K=-273°C=-460°F
100°C=212°F=373 K |
| SI prefixes and conversions | G--M--KHD(b)dcm--μ--n |
| scientific notation | 1=1x10^0
10=1x10^1
100=1x10^2
.1=1x10^-1
.01=1x10^-2 |
| accurate | how right or wrong you are |
| precision | refinement of a measurement |
| significant figures | -all non-zero digits
-not leading zeros
-yes captive zeros
-trailing sometimes
5.200 - yes
5200 - no |
| derived units | combination of units |
| mechanics | physics of motion and forces |
| kinematics | mechanics describing motion with no regard to causes |
| frame of reference | structure used in an experiment to show relationship between objects |
| scalar | has a magnitude but no direction |
| vector | has both a magnitude and direction |
| resultant | vector representing sum of two or more vectors |
| trajectory | parabolic path |
| projectile | object projected into space by the exertion of a force |
| angle at which projectiles are launched the farthest | 45° |
| force | push or pull
SI unit=N |
| contact forces | forces between objects that are touching |
| field forces | forces acting over a distance |
| fundamental forces | - electromagnetic force
- gravity
- strong nuclear force
- weak nuclear force |
| equilibrium | when the sum of all forces acting on an object is 0 |
| inertia | tendency of an object to resist change in motion |
| Newton's first law of motion | motion will not change without external forces acting on it |
| Newton's second law of motion | sum of all forces= mass x acceleration |
| Newton's third law of motion | everything has an equal and opposite reaction |
| energy | ability to cause change |
| potential energy | stored energy |
| acceleration of gravity | 9.81 m/s^2 |
| free fall | motion under the influence of gravity only |
| elastic potential energy vs. gravitational potential energy | elastic potential energy measures stored energy in a spring and gravitational potential energy has to do with how high above ground you are |
| mechanical energy | sum of kinetic energy, elastic potential energy and gravitational potential energy
(ME is conserved in the absence of friction) |
| power | rate at which work is done
SI unit=watts
English unit=horsepower (hp) |
| law of conservation of momentum | initial momentum=final momentum |
