Measurement & Units Before we get into Motion (the first unit we are working on) we need to talk about measurement and how to record measurements

English vs. Metric Units Which is longer? A. 1 mile or 1 kilometer B. 1 yard or 1 meter C. 1 inch or 1 centimeter 1.6 kilometers 1 mile 1 yard = 0.9444 meters 1 inch = 2.54 centimeters

Metric System Most countries have their own system for keeping measurements. You’ve heard of meters, feet, ounces, liters, etc. These are all relatable units. There is also a set of universal units. In science, we use that set of universal units to make our measurements. “SI Units” International System of Units

SI Units Mass : Kilogram (Kg) Length : Meters (m) Time : Seconds (s) Temperature : Kelvin (K) We will use these as standard units, but make sure when you come to a problem that doesn’t use these units, you know how to convert.

Converting Units Kilo x 1000 k Hecto- x100 h Deka- x10 da These are the different prefixes for units: Kilo x 1000 k Hecto- x100 h Deka- x10 da Deci- x0.1 (one tenth) d Centi- x0.01 (one hundredth) c Milli- x0.001 (one thousandth) m

Converting Units 1 Kilometer (km) = 1000 meters So if we look at meters (length): 1 Kilometer (km) = 1000 meters 1 Hectometer (hm) = 100 meters 1 Dekameter (dam) = 10 meters 10 Decimeters (dm) = 1 meter 100 Centimeters (cm) = 1 meter 1000 Millimeters (mm) = 1 meter

Converting Units Which is larger? A. 1 meter or 105 centimeter B. 10 dekameters or 11 meters C. 4 kilometers or 4400 meters D. 12 centimeters or 102 millimeters E. 1200 millimeters or 1 meter F. 70 hectometers or 69 kilometers

Mass vs. Weight Weight the measure of the force of gravity on a object SI Unit: Newtons (N), English Unit: Pounds (lb) This measurement stays the same as long as you are on Earth. Gravity changes as you move further from Earth’s surface, or leave Earth altogether. Mass the amount of matter an object contains SI Unit: Kilograms (kg) This measurement will stay the same regardless of whether you are on Earth or the moon. We think the weight is the same everywhere ... because we all live on the surface of the planet Earth! But if the object were far out in space it would just float around. An object's mass doesn't change (unless you remove some!), but its weight can change.

Volume Volume is the amount of space an object takes up. Common units of volume: m3 cm3 L mL

Density Which object is going to be the heaviest? Which object is physically the biggest? So something smaller can be heavier and something larger can be lighter. DENSITY is the word we use to define this concept.

Density Density is a way of relating size (volume) and mass. We can write density as this equation: Density = SI Unit: Kilogram per cubic meter (kg/m3) Mass Volume Each element on the Periodic Table has a different density, just like feathers and gold have different densities. This is going to be a very important part of Chemistry!

Density – Math Practice A brick of metal has a mass of 57 kg and a volume of 21 cm3. What is it’s density? A wood block has a mass of 57 kg and a volume of 125 cm3. Before calculating, is it more and less dense than the metal?