Measurements

In the USA we are slow to convert to using the international units of measurements. In the USA we use miles, yards, inches, tons, pounds, ounces, gallons, quarts, and ounces. There are many conversions we have to remember.

Measurements The SI units are based on measurement broken down by factors of ten. This makes conversions much easier to remember

KILO 1000 Units HECTO 100 Units DEKA 10 Units DECI 0.1 Unit CENTI 0.01 Unit MILLI Unit Meters Liters Grams Ladder Method How do you use the “ladder” method? 1 st – Determine your starting point. 2 nd – Count the “jumps” to your ending point. 3 rd – Move the decimal the same number of jumps in the same direction. 4 km = _________ m How many jumps does it take? Starting Point Ending Point 4. 1 __. 2 3 = 4000 m

Accuracy vs. Precision Accuracy is how well the results of a measure agree with the real value. Precision is the degree of exactness of a measurement.

Accuracy vs. Precision Real value is 14. Measured data 18,18.5,19, Is it Accurate? Is it Precise?

Accuracy vs. Precision Real value is 14. Measured data results are 20, 8, 12, 16. Is it accurate? Is it precise?

Accuracy vs. Precision Real value is 14. Measured Data is 20,1,3,8. Is it accurate? Is it precise?

Length Length is the distance between two points. The base metric unit of length is the meter. Ex: Rulers, meter sticks, and tape measure

What tools do scientists use to measure length or distance? ruler tape measure meter stick

Measuring Length Ruler: How many millimeters are in 1 centimeter? What is the length of the line in centimeters? _______cm What is the length of the line in millimeters? _______mm What is the length of the line to the nearest centimeter? ________cm HINT: Round to the nearest centimeter – no decimals. 1 centimeter = 10 millimeters

Time Time describes how long events take. The base unit of time is the second. Ex: Clocks, stopwatches, and timers

What is temperature? Temperature is a measure of how hot or cold something is. It is the measure of the heat or thermal energy in a substance. It is the average speed of the particles in a substance.

Department of Mathematics and Science Measuring Temperature There are two different scales we will use to measure temperature. Fahrenheit scale – water freezes at 32 0 and boils at F Celsius (centigrade) scale- water freezes at 0 0 C and boils at C Click on the hyperlink below for an Interactive Thermometer Interactive Thermometer

MASS The amount of matter in an object Does not change with location Uses SI system Base unit kg (kilogram) or grams

Measuring Mass – Triple-Beam Balance Adapted from T. Trimpe st – Place the object on the pan. 2 nd – Slide the large weight to the right until the arm drops below the line. Move the rider back one groove. Make sure it “locks” into place. 3 rd – Repeat this process with the top weight. When the arm moves below the line, back it up one groove. 4 th – Slide the small weight on the front beam until the lines match up. 5 th – Add the amounts on each beam to find the total mass to the nearest tenth of a gram. A triple-beam balance can be used to find the mass of various objects.

Measuring Mass – Triple-Beam Balance A triple-beam balance can be used to find the mass of various objects. The objects are placed on the pan and then you move the weights on the beams until you get the lines on the right-side of the scale to match up. Once you have it balanced, you add up the amounts on each beam to find the total mass. What would be the mass of the object measured in the picture? _______ + ______ + _______ = ________ g Adapted from T. Trimpe

WEIGHT Is a measure of the force of gravity on you. On the moon you would weight 1/6 what you do on Earth. Uses Newtons(N) and grams(g)

What tools do scientists use to measure weight? Spring Scale Pan Scale

VOLUME The amount of space that matter occupies. Common Units – L-Litter – mL-milliliter – Cm 3 - cubic centimeter

What tools do scientists use to measure volume? Measuring cups Graduated cylinders Beakers Measuring spoons Rulers or meter sticks or tape measures

Measuring Volume Graduated cylinders are tools used to find the volume of liquids. Here’s how: Read the measurement based on the bottom of the meniscus or curve.* When using a real cylinder, make sure you are eye-level with the level of the water. What is the volume of water in the cylinder? *What causes the meniscus? 43 mL The liquid in the graduated cylinder generally tends to stick to the sides of the cylinder. That is why for water and similar liquids we read the bottom. Adapted from T. Trimpe

Measuring Volume of Liquids What is the volume of liquid in each cylinder? 52 mL37 mL 22.5mL Adapted from T. Trimpe

Measuring Volume of Solids 10 cm 9 cm 8 cm What tool can be used to measure the volume of an object with the shape of a rectangular prism? We can measure using a ruler and the formula: length ___ x width ___ x height ___ = ______ cm 3 What can be used to measure the volume of irregular shaped object (rock) ? water displacement using a graduated cylinder Amount of H 2 O with object = ______ About of H 2 O without object = ______ Difference = (rock) Volume = ______ Adapted from T. Trimpe

Calculating Volume Volume= length x width x height – Usually used for solids Irregular Objects Use graduated cylinder and calculate how much the water has risen.