Practice:1) How many millimeters are in 4 m? Determine the possible conversion factors: The two units in this problem are m and mm, if 1 m = 1000 mm (103 mm ), then

or

4 m x = 4 x 103 mm Multiply when

converting from larger to smaller units.(4 000 mm)

Practice:2) How many meters are in 54 cm? Determine the conversion factors: The two units in this problem are m and cm, & 1 m = 100 cm, then

or

54 cm x = 0.54 m Divide when converting

from smaller to larger units.

Giga (G) ---------- 109

Mega (M) --------- 106

Kilo (k) ----------- 103

Hecto (h) --------- 102

Deca (da) --------- 101

BASE UNIT (m,L,g,etc)Deci (d) ---------- 10-1

Centi (c) ---------- 10-2

Milli (m) ---------- 10-3

Micro (μ) --------- 10-6

Nano (n) --------- 10-9

Pico (p) --------- 10-12

Practice:3) How many decaliters are in 3 kiloliters? Determine the possible conversion factors: The two units in this problem are daL and kL. 1 kL = 102 daL (because 103-1 = 102 ).

or

3 kL x = 3 x 102 daL Multiply when

converting from larger to smaller units.( 300 daL)

Practice:4) How many nanograms are in 25 decigrams? Determine the possible conversion factors: The two units in this problem are ng and dg. 1 dg = 108 ng (because 10-1-(-9) = 10-1+9 = 108).

or

25 dg x = 25 x 108 ng Multiply when

converting from larger to smaller units.= 2.5 x 109 ng

Practice:4) How many decigrams are in 25 nanograms? Determine the possible conversion factors: The two units in this problem are ng and dg. 1 dg = 108 ng (because 10-1-(-9) = 10-1+9 = 108).

or

25 ng x = 25 x 10-8 dg Divide when converting

from smaller to larger units.= 2.5 x 10-7 dg

Giga (G) ---- 109

Mega (M) --- 106

Kilo (K) ----- 103

Hecto (h) --- 102

Deca (da) --- 101

BASE UNITDeci (d) ---- 10-1

Centi (c) ---- 10-2

Milli (m) ---- 10-3

Micro (μ) --- 10-6

Nano (n) --- 10-9

Pico (p) ---- 10-12

Multiply

Divide

Shift

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mal

poi

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right

Shift

the

deci

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Measurement and SI Units:

Meter (m) for lengthLiter (L) for volumeGram (g) for massSecond (s) for timeKelvin (K) for temperatureJoule (J) for energy

Base units

Derived units are “built” from SI units:

m2

Ex. How can you calculate de area of the football field?How can you calculate de volume of this classroom?

area

volumem3 ; cm3

densityg/cm3

Converting Units:

1 cm = 10 mm

1 cm3 = 101x3 mm3 = 103 mm3

1 cm2 = mm2 101x2 = 102 mm2

1 m = 103 mm

1 m3 = mm3 103x3 = 109 mm3

(1 000 mm3)

(100 mm2)

(1 000 000 000 mm3)

Arithmetic with units:In addition or subtraction the units should be the same: 2 kg + 3 kg = 5 kg 412 m - 12 m = 400 m

3.001 kg + 112 g =

3.001 kg + 0.112 kg = 3.113 kg

4.314 Gm - 0.002 Gm4.314 Gm - 2 Mm = = 4.312 Gm

Arithmetic with units:In multiplication or division: the units must be multiplied or divided too: 3 m × 3 m =

Then, units may cancel: 5 g / 10 g =

9 m2

98 kg m/s2 10 kg x 9.8 m/s2 =

0.5 (no units)

10.00 m/s x 39.37 in/m = 393.7 in/s

Temperature in SI units:

K = oC + 273 oC = K - 273

Temperature in Fahrenheit:

F = 1.8 x oC + 32

oC =

Temperature in SI units:The difference in the two Scales (Celsius, °C & Kelvin, K) is their zero point: - The zero point in Celsius is the freezing point of water. - The zero point on the Kelvin scale is absolute zero. 00 K = - 273°C. (Absolute zero (zero K) is the coldest temperature theoretically possible). You can convert between Kelvin and Celsius by using either of the following equations:

K = oC + 273 oC = K - 273