1 Unit 0 Chapters 1 Mr. Crofoot - PhysicsUnits and Math Unit 0 Chapters 1 Mr. Crofoot Physics

2 8/17/17 Write in Notebook Math ObjectiveUnits Math you need to know

3 8/17/17 Write in Notebook UnitsUnits: the symbols at the end of a value that describes what the value represents. The unit can have a single dimension or multiple dimensions The unit can have a base and multiplicative prefixes 5 m 5 m/sec 500 cm/sec

4 8/17/17 Write in Notebook Adding Values with UnitsYou can only add and subtract values with the same units. If the units are same dimension but not the same unit, one can be converted to match the other before adding or subtracting. 5m + 3ft ≠ 8? 5m + (3ft x 0.305m/ft) = 6m /

5 8/17/17 Write in Notebook Adding Values with Units PracticeCan the following values be added without a unit conversion? 10moles + 7grams (Y/N) 4miles + 6kilometer (Y/N) /

6 8/17/17 Write in Notebook Multiplying Values with UnitsYou can multiply and divide values with any units. The product units are a combination of the factor units. 5m ÷ 3sec = 5/3 m/sec 13.5g ÷ 5.0cm3 = 2.7g/cm3 /

7 8/17/17 Write in Notebook Multiplying Values with Units PracticePerform the following multiplication and division with the values and the units. 20m2 x 5m = __ ____ 33m ÷ 3sec = __ ____ /

8 8/17/17 End of Class and Homework (Two week Sheet)Read: Chapter 1 Answer Review Question 1 /

9 Add the following values. 43.2 meters + 23.2 seconds = 66.4 meters 8/21/17 Starter/Plicker Add the following values. 43.2 meters seconds = 66.4 meters 66.4 meter seconds 20.0 meter seconds These values cannot be added. /

10 8/21/17 Write in Notebook Unit ConversionsTo convert a value with one unit to the value with a different unit, multiply by a ratio with the desired unit on the top and old unit on the bottom. The value represents unity between the units to convert. 5.00𝑚 × 39.4𝑖𝑛 𝑚 = 197 in /

11 8/21/17 Write in Notebook Unit Conversions PracticePerform the following conversions. Write the values and the units. 24𝑔 × 𝑚𝑜𝑙𝑒 12 𝑔 = ___ __ 4𝑚𝐿 × 5 𝑔 𝑚𝐿 = ___ __ /

12 8/21/17 Write in Notebook Adding Significant FiguresWhen adding or subtracting values with significant figures, answer should have same number of digits after the decimal as the additive value with the least digits after the decimal 5.32𝑚+ 250m = 255m /

13 8/21/17 Write in Notebook Adding Significant Figures PracticeAdd the following values and write answer with the appropriate significant figures and units. 10𝑓𝑡 ft = ____ __ 3.04$+ 250$ = ____ __ /

14 8/21/17 Write in Notebook Multiplying Significant FiguresWhen multiplying or dividing values with significant figures, answer should have same number of significant figures as the factor value with the least significant figures. 20.00𝑚 ÷ 5.0sec = 4.0m/sec /

15 8/21/17 Write in Notebook Multiplying Significant Figures PracticeMultiply and divide the following values and write answer with the appropriate significant figures and units. 3.00𝑚 x 5.0m = ____ ___ 16.𝑚 ÷ 4.02 sec = ____ ___ /

16 8/21/17 End of Class and Homework (Two week Sheet)Define the following terms: Significant Figures Hypothesis Law Fact /

17 8/22/2017 Physics Substitute Lesson PlanEclipse Exercise: Combine with Two Week Sheet Plot Thermocouple (°C), Solar Cell (volts) and Photo Resistor data from the Eclipse from 9:00 to 12:00. When was the maximum coverage of the sun by the moon? Which data set (Thermocouple, Solar Cell or Photo Resistor) most directly represents the eclipse phenomenon? Which data set is the most precise and which is the most accurate? What is the difference between a solar eclipse and a lunar eclipse? Explain why solar eclipses are rare. Which is more rare a solar eclipse or lunar eclipse? Why? Watch if possible: https://www.exploratorium.edu/eclipse/video/why-dont-we-have-an-eclipse-every-month

18 Convert 18 meters into miles. There are 1.61 kilometers per mile. 8/23/17 Starter/Plicker Convert 18 meters into miles. There are 1.61 kilometers per mile. 29 miles miles 28.89 miles 0.011 miles /

19 8/23/17 Write in Notebook What Does Math Mean?Addition and Subtraction A + B = C A - B = C Must have the same units to add or subtract!!!!! Answer has the same units!!!! When one variable is held constant, how do the other two variables change together? /

20 8/23/17 Write in Notebook What Does Math Mean?Multiplication and Division A x B = C A ÷ B = C Can have any units to multiply or divide!!!! Answer has the combined units!!!! When one variable is held constant, how do the other two variables change together?

21 8/23/17 Write in Notebook Solving Math Problems?Find all the information that you are given in terms of variables and what equation to use. Figure out what variable you are being asked to determine. Find out what variable information is missing and locate that information. Plug values into equation with units. If the units do not match, then perform unit conversion. Isolate the unknown variable. Solve the number problem. Does it make sense? Solve the unit problem. Does it make sense?

22 8/23/17 Write in Notebook Solving Math Problems?Ideal Gas Law Example: PV = nRT R = (L·atm/mol·K) P = Pressure (atm) V = Volume (L) T = Temperature (K) T(K) = T(°C)x1(K/°C) + 273(K)

23 8/23/17 End of Class and Homework (Two week Sheet)Solve the following problem: If the pressure is P=1.2atm, the volume is V=4.5L and the temperature is 15C, how many moles are present? If the pressure is doubled and the number of moles and temperature are constant, how does the volume change? /

24 8/24/17 Starter/Plicker Using the Ideal Gas Equation: P V = n R TIf the temperature (T) and number of moles (n) stay the same and the pressure (P) is increased, what happens to the volume (V)? Volume increases Volume decreases Volume stays the same Cannot be determined

25 8/24/17 Write in Notebook Scientists Use the Metric SystemExtensive: a property that depends on the amount of material Intensive: a property that does not depend on the amount of material

26 8/24/17 Write in Notebook Scientists Use the Metric System and SI unitsLength Meter (m) Extensive Volume Liter (L) Extensive Mass Kilogram (g) Extensive Time Second (sec) Intensive Temperature Centigrade (°C) Intensive Heat Joule (J) Extensive Count 6.02x1023 (mole) Extensive

27 8/24/17 Write in Notebook Scientists Use the Metric SystemWhen combined with a unit these prefixes change the value by orders of magnitude. Bigger Units Smaller Units Deca or 10 Deci or 0.1 Hecta or 100 Centi or 0.01 Kilo or 1,000 Milli or 0.001 Mega or 1,000,000 Micro or Gega 10+9 Nano 10-9 tera 10+12 Pico 10-12

28 8/24/17 Write in Notebook Scientists Use the Metric SystemMany of units are related by water or based on water: One cubic centimeter (cc) is the volume as one milliliter (mL) One cc or mL of water weighs one gram Water freezes at 0ºC and boils at 100ºC It takes one calorie (4.184 Joules) to heat one gram (g) of water one degree Celsius (ºC).

29 8/24/17 Write in Notebook Scientists Use the Metric SystemPrecision: is how well you can reproduce a measurement Accuracy: is how close the measurement is to the real thing

30 8/24/17 End of Class and Homework (Two week Sheet)When you convert from a small unit to a large unit, what happens to the value of the number? When subtracting from 242.6, which factor determines the number of significant figures in the answer? Explain. Convert the following measurements: 5.70g to kilogram 4.37cm to meters 783 kg to grams 45.3mm to meters 10 m to centimeters 37.5g/mL to kg/l The accepted length of a steel pipe is 5.5m. Calculate the percent error for each of these measurements: (a. 5.2m, b. 5.5m, c. 5.7m, d. 5.1m) Use the accompanying bar graph to answer the following questions. Which substance has the greatest density Which substance has the least density? Which substance has a density of 7.87 g/cm3? Which substance has a density of 11.4 g/cm3? /

31 8/24/17 End of Class and HomeworkTwo Week Sheet is due Friday 8/24/2017 CRAM SHEET Unit 0 is due on Monday 8/28/2017 /

32 8/25/17 Starter/Plicker Heat (with units of Joules) and Mass (with units of grams) are extensive. Joules/gram is often used to describe the heat content of a fuel. Joules/gram is: Extensive Intensive Both Extensive and Intensive Neither Extensive or Intensive

33 8/25/17 End of Class and Homework (Two week Sheet)CRAM SHEET Unit 0 is due on Monday 8/28/2017 /

34 8/28/17 Review CRAM Sheet CRAM SHEET Unit 0

35 8/29/17 Test Unit 0 Test Unit 0