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Sand. Meter Stick. Balance. Spring Scale. Graduated Cylinder. Mass/Volume. Thermometer. Learning Check. What are some U.S. units that are used to measure each of the following? A. length B. volume C. weight D. temperature. Solution. Some possible answers are
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Sand Meter Stick Balance Spring Scale Graduated Cylinder Mass/Volume Thermometer
Learning Check What are some U.S. units that are used to measure each of the following? A. length B. volume C. weight D. temperature
Solution Some possible answers are A.length inch, foot, yard, mile B.volumecup, teaspoon, gallon, pint, quart C.weight ounce, pound (lb), ton D.temperature °F
Stating a Measurement In every measurement there is a • Number followed by a • Unit from a measuring device The number should also be as precise as the measurement!
The Metric System ---The Universal Language of Measurement--- • Metric System – scientists & engineers use this language to communicate • The metric system is based on the number 10 and multiples of 10. • The metric system is often referred to as the International System of Units (abbreviated “SI”).
Some Tools for Measurement Which tool(s) would you use to measure: A. temperature B. volume C. time D. weight
Massa measure of the amount of matter in an object • Kilogram – the basic unit of mass in the metric system 1 kg = 1000 grams
Weighta measure of the attraction between two objects due to gravity • Gravity - a force of attraction between two masses. • Newton (N) - the basic unit of weight in the metric system. • The strength of the gravitational force between two objects depends on the masses of the objects and the distance between them: • The greater the mass, the greater the gravitational force. • The greater the distance between the two objects, the weaker the gravitational force between them.
Mass vs. Weight • An object has a universal mass, but may have different weight depending on gravity. • The mass of an object does not change. • The weight of an object changes as a result of changes in gravity. Weight is only present with gravity. • A pineapple on earth weighs more than on the moon because the earth’s gravity is greater. But the pineapple’s mass always remains the same wherever you go (unless you get hungry and eat it!).
Answer is all of the riders added together!! Think in columns
VolumeThe amount of space an object takes up • Liter – is the basic unit of volume in the metric system 1 Liter = 1 L • Milliliters and Liters are used to measure the volume of liquids • Cubic centimeters – is the metric unit used to measure the volume of solids • A cubic centimeter is equal to the volume of a cube that measures 1 cm by 1 cm by 1 cm (cm3). 1cm • A volume of a cubic centimeter (cm3) is exactly equal to the volume of one milliliter. 1cm 1cm = 1 cm3 = 1 mL
The instrument used to measure volume is a graduated cylinder.
Meniscus The curve in the top surface of the water in a graduated cylinder.
What is the proper way to read a meniscus? Read the ml marking at the bottom of the curve.
Volume of an irregular shaped object Start with a known amount of water. Slowly drop the object into the cylinder. Measure just how much the water goes up.
Densitya measure of the amount of matter that occupies a unit certain volume • Density = mass/volume (units are usually g/mL) • The density of water = 1.00 g/mL • This means that one gram of water occupies one milliliter of volume. • The density of oil = 0.91 g/mL • If lighter fluids float on heavier fluids, do you expect water to float on oil?
Sand grains If the human body is nearly 70% water, is it possible to float in quicksand? Should you get worried?
LengthThe distance between two points Meter – the basic unit of length in the metric system 1 meter = 1 m
Temperaturea measure of how hot or cold something is • Celsius = a unit of temperature in the metric system • Water freezes at 0° C. • Water boils at 100° C. • Normal body temperature is 37° C • Room temperature is 21° C.
Temperature Conversions ! Celsius to Fahrenheit F=(C x 9/5) + 32 Fahrenheit to Celsius C=(F-32) x 5/9
Some Tools for Measurement Which tool(s) would you use to measure: A. temperature B. volume C. time D. weight
Learning Check Match L) length M) mass V) volume ____ A. A bag of tomatoes is 4.6 kg. ____ B. A person is 2.0 m tall. ____ C. A medication contains 0.50 g Aspirin. ____ D. A bottle contains 1.5 L of water. M L M V
Learning Check Select the unit you would use to measure 1. Your height a) millimeters b) meters c) kilometers 2. Your mass a) milligrams b) grams c) kilograms 3. The distance between two cities a) millimeters b) meters c) kilometers 4. The width of an artery a) millimeters b) meters c) kilometers
Solution 1. Your height b) meters 2. Your mass c) kilograms 3. The distance between two cities c) kilometers 4. The width of an artery a) millimeters
