** The study of the physical world. Table 1-1 Areas within physics (Page 5 in your text) Name Subjects Examples Mechanicsmotion and its causesfalling objects, Friction, weight Spinning objects Thermodynamicsheat and temperaturemelting and freezing, engines refrigerators Vibrations andspecific types of repetitive springs, pendulums, sound Wave phenomenamotions Opticslightmirrors, lenses, color, astronomy Electromagnetism electricity, magnetismelectrical charge, circuitry, and light permanent magnets, electromagnets Relativity particles moving at anyparticle collisions, particle speed, including veryaccelerators, nuclear energy high speeds Quantum mechanicsbehavior of subatomic andthe atom and its parts microscopic particles ** Study involves the use of a small number of basic concepts, equations, and assumptions.

Example: Flight of an object projected into the air. I.Make observations and collect data that leads to a question. II. Formulate and objectively test hypotheses by experimentation. III.Interpret results, and revise the hypothesis if necessary. IV. State conclusions in a form that can be evaluated by others. Who uses this method of solving problems? Everybody!!! A replica or description designed to show the structure or workings of an object, system, or concept. System: A set of items or interactions considered a distinct physical entity for the purpose of study.

SI Base Units Derived Units SI Unit QuantityNameSymbol Timeseconds Lengthmeterm Masskilogramkg Substance amountmolemol TemperatureKelvinK Electric currentampereA Luminous intensitycandelacd Derived units : any unit that is composed of more than one base unit and was formed by combining base units using multiplication or division. Examples include…. Quantity SI Units Other units used Density kg/L, g/mL, g/cm 3 Force N (Newton), kg·m/s 2 Volume L (liter), m 3, cm 3, Energy J (joule), kg·m 2 /s 2 N·m Acceleration m/s 2 Velocity m/s Numerical measurements always must be accompanied by some sort of scientific unit. Parallax: An error of measurement because the measurer does not read the instrument in a direct line to the measuring scale. Système International (SI) Units

The Axis A. The independent variable is normally plotted on the x-axis. B. The dependent variable is plotted on the Y-axis.. Title A. Main Title should tell what the graph describes. B. Subtitle: (quantity on the Y-axis) vs (quantity on the X-axis) C. Example: Acceleration (m/s 2 ) Force (N) vs Mass (kg)

Slope ΔY (dependent variable) ΔX (independent variable) Data can be collected and graphed to obtain scientific scientific relationships. Data for speed is commonly collected and graphed Speed Distance Time This indicates if you want speed to be determined by the slope of your graph you need to have distance as the dependent (y) variable and time as the independent (x)variable What happens with F = maSince F = ma, F/a = m and F/m = a “F” will always be the dependent variable and “m” or “a” must be the independent variable. Graphs

Linear graph: Equation  y = mx + b m = slope b = y-intercept (y-intercept always has coordinates of (0, y)) Linear graphs always use the best fit line. Linear graphs indicate direct proportionality Hyperbolic graphs: Equation  y = k/x Where k = some constant value Hyperbolic graphs indicate inverse proportionality Parabolic graphs: Equation  y = kx 2 or x = ky 2 The y = kx 2 is most commonly used. Again, k = some constant value Parabolic graphs (y = kx 2) indicate the dependent variable increases at a faster rate than the independent variable. Best-fit line Y vs X Speed Distance (m) vs Mass (kg) Graph Types

Calculating with Significant Digits Add or subtract: Round the answer to the most precise place holder appearing in all data N N = 123 N Why? N – N = N = N Why? Because both numbers have a tenths digit. See rules for rounding J x 106 J = 1840 J 2 Why? See Table 1.5 & 1.6 on pages 18 & 19. Because both numbers have a ``ones digit. There are 3 significant digits in n 2 / n = n Why There are 4 sig figs in Multiply or divide : Round the answer to the number of digits present in the data number with the smallest number of sig fig’s.

The Metric System…. Prefixes indicate the power of 10 used with metric base units. Powers of 10 with a negative exponent are small in size g means it would take 1000 little parts to make up one gram g means it would take a trillion little parts to make up one gram. 1 cm 3 = 1 mL1 dm 3 = 1 L Recall!!! Know these Powers of 10 with a positive exponent are large in size 10 3 g means there are 1000 grams present g means there are a trillion grams.

Describing Experimental Uncertainty Precision Precision describes the repeatability (deviation) of a measurement, or the quality of the measurement instrument. Reading Uncertainty depends on the experience (and possibly arrogance) of the observer. Example: The meter stick can be read to about + 1 mm Random errors must be described by statistical analysis. %D = Lit value- Exp. value 100 Lit Value Precision is the combination of the reading uncertainty of the instrument and random errors in the measurement process. Percent Deviation:

Accuracy Accuracy reflects how close the experimenter is to the accepted literature values. PRECISIONPRECISION ACCURACY ACCURACY If no accepted standard exists, accuracy can be very difficult to assess.

Dimensional Analysis Dimensional Analysis is a process by which you use units to help solve or verify the problem outcome. The radius of a circle inscribed in any triangle whose sides are a, b, and c is Given by the following equation, in which s is an abbreviation for (a + b + c)  2. Check this formula for dimensional consistency. The period of a simple pendulum, defined as the time necessary for one complete oscillation, is measured in time units and is given by the r = (s – a)(s – b)(s – c) s Equation: t = 2  L/g Where L is the length of the pendulum and g is the acceleration due to gravity, which has units on length divided by time squared. Check this equation for dimensional consistency.

Order-of-magnitude is a power of ten estimate instead of an actual numerical value. Estimate the number of times your heart beats in a day, your age in seconds and how many breaths you will have taken in 70 years of life. Order Of Magnitude Approximately how long will it take a car to travel 725 km if it moves with a speed of 88 km/h? 725 km is closer to (1000) 10 3 than (100) 10 2, 88 km/h is closer to (100) Since speed = distance, we must solve for time. time time = distance / speed. So 10 3 km = 10 h 10 2 km/h The actual answer is 8.2 h. Order of magnitude gives you an estimate so you can feel comfortable with your answer.