Presentation on theme: "***METRICS***. Measurement What is measurement? –any standard of comparison, estimation, or judgment."— Presentation transcript:
Measurement What is measurement? –any standard of comparison, estimation, or judgment
Why do we measure things? –To give information – To compare things quantitatively (if a person had never seen or heard of these animals before, measurements would help that person compare them) –Length of a crocodile compared to a gecko –Height of a Basketball player, compared to horse jockey –Weight of an elephant, compared to mouse
What kinds of measurements can you take? –Length –Volume –Mass –Temperature
U.S.A What kind of scale does the U.S. use? –U.S. Customary scale Including inches, feet, miles
The World & The Scientific Community –Uses the SI Systeme Internationale d’Unites (French), or Metric System –As early as the 17 th century French scientist found it illogical to have so many measurement systems so they developed one universal system. It is easy to use because it is in multiples of 10 Today all countries except the United States, Burma, and Liberia use the metric system
Why is it important to use only one scale of measurement in science? –Scientists need to be able to share and compare their work with other scientists easily. –It makes it less confusing!
Length Basic unit of measure = meter What would you measure in meters? –1. How far you throw a softball –2. A person’s height –3. Measure height of a room’s wall
Units for metric length UnitAbbreviationMeaning 1.KilometerKm1000m 2.HectometerHm100m 3.DekameterDkm10m 4.Meterm1m 5.Decimeterdm.1m 6.Centimetercm.01m 7.Millimetermm.001m
Multiples of Ten 10 Hm = 1 Km 10 Dkm = 1 Hm 10 m = 1 Dkm 10 dm = 1 m 10 cm = 1 dm 10 mm = 1 cm
K ing H enry D ied M aking D ead C ows M oo
K ing Kilometer H enry Hectometer D ied Dekameter M aking Meter D ead Decimeter C ows Centimeter M oo Millimeter
Let’s Practice! Length *Measure from the zero mark not the end of the ruler (meter stick) What is the measurement? Cm
What is the measurement? 263 mm 26.3 cm 2.63 dm m Cm
8 109 What are these measurements in centimeters, and millimeters? A BC Cm One More, On Your Own
Measuring Mass Using a triple beam balance 1. Place object on the pan 2. Move rider on the middle beam notch by notch until the horizontal pointer drops below zero. Move the rider back one notch 3. Move the rider on the back beam notch by notch until the pointer again drops below zero. Move the rider back one notch. 4. Slowly slide the rider along the front beam until the pointer stops at the zero point. 5. The mass of the object is equal to the sum of the readings on the three beams.
Mass vs. Weight Mass – the amount of matter an object contains (the amount of stuff) IT DOES NOT CHANGE Weight- force of gravity on an object –Can vary depending on location of object. Example: –Your mass is the same on the moon and on the earth. –Your weight is different on the moon as compared to the earth. You weigh less on the moon because the force of gravity is less on the moon.
Units for measuring mass: Unit Abbreviation Meaning 1. KilogramKg1000g 2. Hectogram Hg100g 3. DekagramDkg10g 4. Gramg1g 5. Decigramdg.1g 6. Centigramcg.01g 7. Milligrammg.001g
Temperature Unit of measure : Celsius (C ) Example: –Water freezes at 0° C and boils at 100° C
Time Time is simply distinguishing which of two events is earlier and which later Time is measured in different increments Years Months Days Hours Minutes Seconds
Volume and Density
Volume - The amount of space an object takes up.
Measuring Volume Liquids –Unit of measure = Liters (L) or (ml) –Use a graduated cylinder –Measure from the bottom of the meniscus Meniscus –the curved surface of a liquid
Measuring Volume Regular solids –Unit of measure = cubic centimeter (cm 3 ) –Volume= length x width x height Or L x W x H= Volume Example –Volume = 20cm x 6cm x 25cm = 3000 cm 3
Irregular Solids Unit of measure= centimeters cubed (cm 3 ). BUT! Measured using ml –ml and cm 3 are equivalent units! Example: –Volume of a rock using a graduated cylinder
Density Density: How much mass in a given volume (How much “stuff” in a certain amount of “space”) Formula: Density = massD = M volume V
Example: –A box has a mass of 400 g and a volume of 15 cm 3. What is the density of the box? Example: –Bowling ball vs. Beach ball Same volume different mass Which item is more dense?