Units of Measurement What are some different ways of measuring a person’s height? There are two major systems of units used today. Which one do we use in the United States? Scientist have developed an International System of Measurements (SI), so that every one will use the same units of measurements, making sharing data results easier.

7 basic metric units Quantity Metric System British System Length Mass Time Temperature Electric Current Amount of Substance Luminous Intensity

Metric Prefixes Prefix Symbol Meaning Multiple giga mega kilo deca deci centi milli micro nano

Derived Units Derived units are combinations of the seven basic units and are used to describe other measured quantities in nature. How do you measure the speed of a car on the highway? What are some examples of other derived units?

Density Density is a common derived unit comparing the mass and volume of an object. What is the equation for density?

Density Two blocks are on a table. Block A has a volume of 30.0 cm3 and a mass of 81.0 g. Block B has a volume of 50.0 cm3 and a mass of 135 g. Which block has the greater density? What would the volume be of a third block that has a mass of 23.0 g if it has the same density as block B?

Conversions kilo hecto deca Base Unit (1) deci centi milli k h da Meter (m) d c m 1000 100 10 Gram (g) 0.1 0.01 .001 103 102 101 Liter (l) 10-1 10-2 10-3 Move the decimal point to the left or right to convert within the metric system. If you are going from a smaller unit to a larger unit __________________________________ If you are going from a larger unit to a smaller unit __________________________________

Metric Conversions 245 m = _____________ cm 305 kg = _____________ g 35 mm = ______________ m 1250 cm = _____________ m 358 ml = ______________ l 2350 g = ______________kg 35 dm = ______________m 67 hm = ______________m

Factor Label Conversions A football field is 100 yards long. How long is that in meters? A horse can gallop at a speed of 42.0 mph. How fast can the horse gallop in m/s?

Examples If I were to hit a home run down the left side of Jacobs Field the ball would have to travel at least 325 ft. How far is that in meters? The top speed of a human is 10.4 m/s. How fast is that in mph?

Examples A race car can travel around 225 mph. How fast is that in m/s?

Examples Gold has a density of 19.30 g/cm3. What is its density in lbs/in3 ?