Foundations of Physics CPO Science Foundations of Physics Unit 1, Chapter 2

Unit 1: Measurement and Motion Chapter 2: Measurement and Units 2.1 Distance and Length 2.2 Time 2.3 Mass, Matter and the Atom

Chapter 2 Objectives Express lengths in metric and English units. Convert distances between different units. Calculate the surface area and volume of simple shapes. Describe time intervals in hours, minutes, and seconds. Convert time in mixed units to time in seconds. Describe two effects you feel every day that are created by mass. Describe the mass of objects in grams and kilograms. Use scientific notation to represent large and small numbers.

*Students read Section 2.1 AFTER Investigation 2.1 2.1 Distance and Length Key Question: How do we accurately communicate length and distance? *Students read Section 2.1 AFTER Investigation 2.1

Chapter 2 Vocabulary Terms meter centimeter millimeter kilometer inch foot mile surface area volume weight metric system conversion factor time interval precision accuracy kilogram gram mass English system atom inertia molecule mixture element base power of ten exponent scientific notation distance length

2.1 Distance and Length measurement - a quantity and a unit distance - is a length the amount of space between two points

2.1 Two Systems of Units Science problem solving requires both: Metric system English system

2.1 Units of Length The common units of measurement in the English system are inches, feet, yards, and miles. These four length units are related to the meter.

2.1 Convert Units conversion factor - is the number by which you multiply or divide a quantity in one unit to express the quantity in a different unit.

2.1 Convert length A football field is 100 yards long. What is this distance expressed in meters? 1) You are given distance in yards. 2) You are asked to find distance in meters. 3) 1 yard = 3 feet, 1 foot = 0.3048 meters 4) Solve: 100 yards = 3 feet/1 yard x .3048 m/1 foot = 91.4 m

2.1 Surface Area vs. Volume surface area - is the measurement of the extent of an object’s surface or area without including its thickness. volume - is a measure of the space occupied by a object.

2.1 Calculate surface area and volume A basketball has a radius of 12.5 centimeters. Calculate the surface area and volume of the ball. You are asked to find surface area and volume. A ball is shaped like a sphere and you are given the radius. Surface area: A = 4πr2; volume: V = (4/3)πr3 Solve... 1) You are asked to find surface area and volume. 2) A ball is shaped like a sphere and you are given the radius. 3) Surface area: A = 4 π r2; volume: V = (4/3) π r3 4) Solve: A= 4 (3.14)(12.5)2 = 1,963 cm2 V = (4/3)(3.14)(12.5)3 = 8,181 cm3

*Students read Section 2.2 AFTER Investigation 2.2 2.2 Time Key Question: How do we measure and describe time? *Students read Section 2.2 AFTER Investigation 2.2

2.2 Time Two ways to think about time: What time is it? 3 P.M. Eastern Time on April 21, 2004, How much time has passed? 3 hr: 44 min: 25 sec. A quantity of time is often called a time interval.

2.2 Converting Mixed Units You are asked for time in seconds. You are given a time interval in mixed units. 1 hour = 3,600 sec 1 minute = 60 sec Do the conversion: 1 hour = 3,600 sec 26 minutes = 26 × 60 = 1,560 sec Add all the seconds: t = 3,600 + 1,560 + 31.25 = 5,191.25 sec

2.2 Time Units

2.2 Accuracy and Precision is the quality of being exact and free from error. how close a measurement is to the true value. precision is the degree of mutual agreement among a series of individual measurements, values, or results.

2.3 Mass, Matter and the Atom Key Question: How is mass described? *Students read Section 2.2 AFTER Investigation 2.3

2.3 Mass, Matter and the Atom is the amount of “stuff” an object contains. Two effects mass has on matter: weight is the force of the Earth’s gravity pulling down. Gravity acts on an object’s mass. inertia is the tendency of an object to resist changes in motion. Inertia comes from mass.

2.3 Measuring Mass kilogram - is the mass of 1 liter of water or 1,000 cubic centimeters of water.

2.3 Scientific Notation Scientific notation works by expressing very small or very large numbers as the product of two numbers that are individually much easier to deal with. The first number is called the base. The second number is a power of ten. The base is usually written with only one digit in front of the decimal point. ex. 2,500 would be written 2.5 × 103 The small numeral 3 in 103 is called the exponent.

2.3 Mass, Matter and the Atom the smallest particle of an element that can exist alone or in combination with other atoms. element composed of all of the same kind of atom.

2.3 Mass, Matter and the Atom molecule - is a neutral group of atoms that are chemically bonded together; it is the smallest particle of a compound that can exist by itself and retain the properties of the compound. mixture - is a substance that contains a combination of different compounds and/or elements and be separated by physical means.

2.3 Mass, Matter and the Atom The three most common forms of matter are called solid, liquid, and gas. At temperatures greater than 11,000 °C the atoms in a gas start to break apart and form plasma.

2.3 Mass, Matter and the Atom Solids - Atoms in a solid stay together because the energy per atom is too low to break the bonds between atoms. Liquids- Liquids flow because atoms have enough energy to move around by temporarily breaking and reforming bonds with neighboring atoms. Gases- Gas atoms have enough energy to completely break bonds with each other. Plasma- In plasma, matter becomes ionized as electrons are broken loose from atoms.

Application: Nanotechnology miniature cell pump micro T.V. mirrors smaller than insect legs