Would you be breaking the speed limit in a 40 mi/h zone if you were traveling at 60 km/h? one kilometer = 0.62 miles 60 km/h = 37.2 mi/h You would not be speeding! km/h and mi/h measure the same quantity using different units.

Measurements in Science Here are some pretty fascinating animal measurements. A newborn giraffe stands 1.8 meters tall. A colossal squid’s eye measures about 28 centimeters across With a mass of only 20 grams, the rhinoceros beetle can lift 850 times its own mass When a blue whale exhales, the spray from its blowhole can reach up to 9 meters into the air. NOW….. GET WITH A PARTNER AND ASNWER THE FOLLOWING QUESTIONS 1: What problems could arise if some scientists measured length in inches and others measured length in centimeters? 2: What do you think the unit of measurement you would use to measure your height and mass would be?

Key Vocabulary Metric System International System of Units (SI) Mass Weight Volume Density A standard measurement system is important because it allows scientists to compare data and communicate with each other about their results.

Metric System The Metric System is a measurement system based on the number 10. Modern scientists use a version of the metric system called the International System of Units (SI). EX: Standard measurement is important because without it, cooks would use handfuls and pinches instead of cups and tablespoons.

The Fundamental SI Units Physical Quantity Name of Unit Abbreviation Mass kilogram kg Length meter m Time second s Temperature kelvin K Electric current ampere A Amount of substance mole mol Luminous intensity candela cd

Common SI prefixes Prefix Meaning Kilo- (k) 1,000 Hecto – (h) 100 Deka- (da) 10 No prefix 1 Deci – (d) 0.1 (one tenth) Centi- ( c ) 0.01 (one hundredth) Milli (m) 0.001 (one thousandth)

100 times larger! Lets apply what we know! Calculate: How many times larger is a kilo- than a deka- ? 100 times larger!

Practice: In each pair below, circle the larger Millimeter Centimeter picometer Micrometer kilogram Hectogram deciliter milliliter

Length A Meter (m) is the basic SI unit used for measuring length. One tool used to measure length is a metric ruler. Example: You can measure how far you kick a soccer ball in meters. For measuring things smaller than a meter, you use the centimeter (cm) and millimeter (mm). Example: The length of your sheet of paper is about 28 centimeters. For measuring a long distance, such as the distance between two cities, you use the unit called a kilometer (km)

Mass Mass is a measure of the amount of matter in an object. A balance would be used to measure mass A balance compares the mass of an object to a known mass. In SI, the basic unit for measuring mass is the Kilogram. If you want to measure much smaller masses, you would use grams(g_ or milligrams (mg). Things that you would measure in kilograms are the mass of: Cars, Bikes, and People. (larger masses) **1 kg = 1,000 g** **1 g = 1,000 mg**

Mass is the amount of matter, weight is a measure of the gravitational pull on matter

Weight Weight is different than mass. Weight is a measure of the force of gravity acting on an object. A scale is used to measure weight. When you stand on a scale, gravity pulls you downward. Weight and mass are different because The mass of an object stays the same, and the weight of an object changes. EXAMPLE: On the moon the force of gravity is weaker than on earth. So you weigh less on the moon than you do on earth, but your mass is the same no matter where you are.

VOLUME Volume is the amount of space an object or substance takes up. All objects with mass whether they are solids, liquids, or gases, have volume. In SI, the common units for measure the volume of solids include the cubic meter (m3), and the cubic centimeter (cm3). The liter is typically used to measure the volume of liquids. EX: LITER OF PEPSI

Volume: Liter (L) and the milliliter (mL) 10 cm 10 cm A liter is a cube 1 dm3 = 10 cm long on each side. 10 cm 1 L = dm3 = (10 cm)3 = (10 X 10 X 10) cm3 = 1000 cm3 = 1000 mL or 1mL = 1/1000 L Cubic centimeter A milliliter (mL) is a cube 1 cm long on each side.

LETS APPLY OUR KNOWLEDGE OF VOLUME! On a sheet of paper, write down the answer to the following question, quietly and independently. WHAT UNIT OF MEASURE WOULD YOU USE TO MEASURE THE VOLUME OF THE WATER IN A BATHTUB? WHAT UNIT OF MEASURE WOULD YOU USE TO MEASURE THE VOLUME OF A TEXT BOOK?

ANSWERS: YOU WOULD USE A LITER TO MEASURE THE VOLUME OF THE WATER IN A BATH TUB. YOU WOULD USE A CUBIC CENTIMETER TO MEASURE THE VOLUME OF A TEXT BOOK

Density Two objects of the same size can have different masses. This is because different materials have different densities Density is a measure of how much mass is contained in a given volume. Density is made up of two measurements, mass and volume. Because of that the SI unit for measuring density is kilograms per cubic meter. Once you know an objects density, you can determine whether the object will float in a given liquid. An object will float if it is less dense than the surrounding liquid. EX: a piece of wood with a density of 0.8 g/cm3 will float in water, while a ring made of pure silver that has a density of 10.5 g/cm3 will sink.

D = Density: m V = A Physical property of a substance, defined as: Amount of matter (# atoms) per unit volume = compactness. the mass divided by the volume. = D = m V Mass (g) Volume (mL)

Temperature Temperature is measured using a thermometer. A thermometer has numbers and units, or a temperature scale on it. There are two temperature scales that are used in science: The Celsius scale, and the kelvin scale. The kelvin is useful in science because there are no negative numbers THE KELVIN SCALE IS THE official BASIS FOR THE SI TEMPERATURE UNITS00

K = C + 273.15 F = 1.8(C) + 32 C = (F − 32) 1.8

TIME Time is a measurement of the period between two events. The SECOND is the SI unit used to measure time. Just like every other SI units, the second is divided into smaller units based on the number 10. EXAMPLE: Millisecond (ms) is a thousandth of a second. You use minutes and hours for longer units of time. Clocks and watches are used to measure time. Some clocks are more accurate than others.