List an example of things measured by mass, volume, and length. Agenda for Wednesday Sept 24th Go over test Measurement notes Measurement practice

Accuracy & Precision Accuracy: Precision: Freedom form mistakes or errors; Correctness Precision: The ability to repeat; Repeatability

Units of Measurement International System of Units (SI) Quantity Base Unit Abbreviation Length Meter m cm, mm, km Mass Kilogram kg g, mg Time Second s Temperature Kelvin K **Celsius (C)

Linear Measurement (straight lines) Length, Width, Height Tool: Meter stick, ruler Base unit of measurement: Meters (m)

Area How much surface an object covers Units: Formula: m2, cm2 , etc. A = L x W

Volume How much space an object takes up Two types: Regular and irregular Regular solids are box like Volume is found by measuring length, width, and height The volume of irregular objects is found by water displacement

Volume (cont.) Tool: Units of measurement: 1cm3 = 1ml Regular = ruler or meter stick Irregular = graduated cylinder Units of measurement: m3, cm3 (for solids) L , ml (for liquids) 1cm3 = 1ml

Volume of Regular Objects Boxes: V = L x W x H Spheres Formula : V = 4/3 πr3 Cylinder Formula: V = πr2 h *π = 3.14

Measuring spheres/circles Measure end to end Use paper on edge of spheres Measured diameter we need radius Radius = ½ diameter So: if d = 10 then r = 5

How many decimals?

What is accuracy? Precision? Agenda for Thursday Sept 25th Go over test Measurement pre-lab Measurement lab

Volume lab Rounding What was the smallest number of digits in any of my measurements? You would then round off your calculated value to the smallest number of digits in your measurements.

Example: If L = 2.11 cm, W = 4.3212cm and H = 7.10cm, 7.10cm has the smallest number of digits so your calculated value would be rounded to three digits. 2.11 x 4.3212 x 7.10 = 64.735897 would be rounded to 64.7

Three students reported the length of a pencil to be 12 cm, 12 Three students reported the length of a pencil to be 12 cm, 12.0 cm, and 12.00 cm. Do all three readings contain the same information? Which one has the most? Why? Agenda for Friday Sept 26th Measurement lab

How do you decide how much water is in the cylinder? How much water is there? Agenda for Monday Sept 29th Volume of Irregular objects

What is the volume of a box with the following dimensions: Width = 3 What is the volume of a box with the following dimensions: Width = 3.45 Length = 2.56 Height = 1.89 Agenda for Tuesday Sept 30th Finish Measurement notes Metric Conversion Notes Density

Mass Definition: Tool: Base unit: 1g = 1cm3 for water only The amount of matter in an object Tool: Triple beam Balance Base unit: Grams (g) A penny has the mass of about 1g 1g = 1cm3 for water only

Making a connection When you use water (this works only for water) 1 ml = 1 cm3 = 1 g

Weight Definition: Tool: Base unit: The gravitational pull on an object Tool: Scale Base unit: Newton (N)

Mass Vs. Weight

Temperature Definition: Tool: Base unit: Measurement of the average kinetic energy of molecules Tool: Thermometer Base unit: Celsius (co) and Kelvin (ko)

Density Def. – ratio of the mass of a substance to the volume of a substance Formula: D = m/V Density = mass/volume Units: g/cm3 Low density means atoms are not as packed together

Density Density determines whether an object will float or sink Less dense objects float Water has a density of 1 g/cm3 Use density to find substances lab

Density Problems If 12.0 cm3 has a mass of 9.17 g, what is the density? If an object has a density of 4.2 g/cm3 and a mass of 30 g, what is its volume?

Explain how you would find the volume of an irregular shaped object. Agenda for Monday Jan 13th Finish notes Go over worksheet Mass lab

What is the difference between mass and weight? Agenda for Tuesday Jan 14th QUIZ Density Start lab TEST TUESDAY

What is density? Agenda for Wednesday Jan 15th Demo Lab/worksheet