SCIENTIFIC MEASUREMENT THE METRIC SYSTEM International System of

SCIENTIFIC MEASUREMENT [THE METRIC SYSTEM] International System of Units (SI) measurement system used by scientists around the world to express measurements made in scientific investigations [the Metric System].

n Scientists all over the world know and use the metric system.

n Below is a list of the basic units of the metric system (SI system) and the commonly used prefixes with their meanings.

What units are used when measuring objects? n n n Basic SI units: – meters (m) - length – grams (g) - mass – liters (L) – volume – seconds (s) – time – Celsius degree (o. C. ) – temperature Prefixes: see table → The metric system is used for all over the world (except the USA) Used for all SCIENTIFIC measurements (incl. the USA) SI stands for… Systeme Internationale

BASIC UNITS OF THE METRIC SYSTEM BASIC UNIT meter (m) PROPERTY MEASURED length gram (g) Mass liter (L) Volume second (s) Time Celsius degree (Co) temperature

COMMON PREFIXES AND THEIR MEANINGS PREFIX (abbreviation) kilo – (k) hecto – (h) MEANING 1, 000 ( 1 thousand) 100 (1 hundred) deca- or deka- (da or dk) deci- (d) centi- (c) 0. 1 ( tenth) 0. 01 (1 hundreth) milli- (m) 0. 001 (1 thousandth) 10 (ten)

How are we going to remember this? ? ? King n Henry’s n darned n MONEY (GOLD, LOOT) n didn’t n come n Monday. n

How do we convert in the Metric system? n Walk along the “Metric Sidewalk…. . ”

THE METRIC SIDEWALK: k h da or dk (unit) d c m -Move decimal point to the RIGHT if you walk to the RIGHT. - Move the decimal point to the LEFT if you walk to the LEFT.

PRACTICE: 1. 2. 3. 4. 5. 6. 7. 0. 0023675 23. 675 cm = _______ hm 560 56 dm = _______ cm 0. 00014356 14. 356 mg = _______ hg 12, 000 12 k. L = _______ L 698, 000 6. 98 hg = _______ mg 0. 009 9 m = _______ km 0. 00006854 6. 854 c. L = _______ k. L

More Practice: 8. 9. 10. 3. 65 mg 9. 987 g 12. 203 km mm = = = 0. 0365 _______ dg 0. 09987 _______ hg 12, 203, 000 _______

More Practice! Quiz Tomorrow!!! n 1. 8. 92 m = ________ cm n 2. 5000 cm = ________ m n 3. 5 km = _________ m n 4. 39, 000 hm = _______ m

Even more practice! n Kim and Meghan live on opposite sides of town. On Sundays they ride their bicycles and meet at the soccer field. Kim rides 2. 3 km, and Meghan rides 2129 m. – (a) Who has the longer ride? _____ – (b) How did you figure this out.

Temperature Scales Fahrenheit – used in USA n FP of water = 32 o. F. n BP of water = 212 o. F. n Room temp. = 67 o. F. n Body temp. = 98. 6 o. F. n

Temperature Scales Celsius (Centigrade) – used everywhere else n FP of water = 0 o. C. n BP of water = 100 o. C. n Room temp. = 20 o. C. n Body temp. = 37 o. C. n

Temperature Scales Kelvin – degrees above absolute zero n FP of water = 273 o. C. n BP of water = 373 o. C. n 0 K = -273 o. C. n O K = -460 o. F. n

Measuring Mass Triple-beam balance n First zero the balance n Move sliders; make it balance n Measure to nearest 0. 01 g n

How could you measure the mass of a liquid? n n n Step 1 – Step 2 – Step 3 – Step 4 – Step 5 – n n n Meas. mass of grad. cylinder Put liq. in Meas. mass of grad. cyl. plus liq. Subtract Add correct units

Measuring Volume of a liquid Graduated cylinder n NOT a beaker!!!!! n Read at eye level n Bottom of meniscus n 1 ml = 1 cm 3 n

Measuring Volume of a solid Cube: V = l 3 n Right rectangular prism: V = l w h n Cylinder: V = (4/3) π r 2 h n Cone: V = (1/3) π r 2 h n Sphere: V = (4/3) π r 3 n Irregular solid: use the water displacement method! n