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Physics. Science 1206 Unit 4: Motion. Physics : the science that deals with matter, energy, motion and force. Measurement, Units, & Error. How would you describe this motion?. Measurement, Units, & Error. Qualitative: Description of observation, not measured
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Science 1206 Unit 4: Motion Physics: the science that deals with matter, energy, motion and force
Measurement, Units, & Error How would you describe this motion?
Measurement, Units, & Error Qualitative: Description of observation, not measured example: big/small, quiet/loud, fast/slow Quantitative: Numerical, measured example: 7ft tall, 30 km/hr Which is more useful? Max50km/hr GO SLOW
Measurements, Units, and Error Units -Most measurements are useless to us without units This building is 8 Pats tall This cat weighs 52 -Using inappropriate units also causes confusion SPEED MAX 20,000 mm/s
Measurement, Units, & Error SI Units http://www.youtube.com/watch?v=g0OAFS5K8h8
Measurement, Units, & Error SI Units- Le Systeme International d'Unites -single system agree on by scientists worldwide - seven base units + other derived units These are the ones we will use
Measurement, Units, & Error Derived units- the ones we get from manipulating (adding, dividing, multiplying) existing base units Examples: Area= Length x Width Speed= Distance / Time Area= m x m = m2 Speed= Km/ hr or m/s 5m 50 km in 1 hr = 50 km/hr 50 km in 1/2 hr = 100 km/hr 6m
Measurement, Units, & Error k h da Base d c m
Measurement, Units, & Error Converting Units k h da Base d c m kilo hecto deka deci centi milli King Henry's Daughter Bakes Delicious Chocolate Muffins Left to Right = x10 Right to Left = /10 *Time
Measurement, Units, & Error Practice converting the following: a) 31.6 cm = ______m b) 2.6 kL = _____mL c) 40 g = ______ mg d) 2000 hm = _____km e) 45 g = ________kg f) 1 200 mm = ______km Remember! k h da Base d c m kilo hecto deka deci centi milli
Measurement, Units, & Error Converting Derived Units Ex: Convert 100 km/hr to m/s 100 km 1 hr 60min 1000m x x x = 27.8 m/s 1hr 60 min 3600 sec 1km Hint: To change from km/hr to m/s ÷ by 3.6 To change from m/s to km/hr x by 3.6
Measurement, Units, & Error Converting Derived Units Ex. Convert 5700 cm2 to m2
Measurement, Units, & Error Converting Derived Units Ex. Convert 5700 cm2 to m2 5700 cm x cm 1m 1m x x 1 = 0.57 m2 100 cm 100 cm
Measurement, Units, & Error Converting Derived Units Ex. Convert 5700 cm2 to m2 5700 cm x cm 1m 1m 1 100 cm 100 cm x x = 0.57 m2 -For a unit2 times the number of decimal places you otherwise move by 2 -For a unit3 times the number of decimal places you would otherwise move by 3
Measurement, Units, & Error Converting Derived Units Ex. Convert 5700. cm2 to m2 x x 1 = 0.57 m2 5700 cm x cm 1m 1m 100 cm 100 cm -For a unit2 times the number of decimal places you otherwise move by 2 -For a unit3 times the number of decimal places you would otherwise move by 3
Measurement, Units, & Error Converting Derived Units Ex. Convert 4300 mm3 to cm3 Remember! -For a unit2 times the number of decimal places you otherwise move by 2 -For a unit3 times the number of decimal places you would otherwise move by 3
Measurement, Units, & Error Converting Derived Units Ex. Convert 4300 mm3 to cm3 - mm to cm is 1 decimal place to the left - mm3 to cm3 should be 3 decimal places to the left 4300.0 mm3 = 4.3cm3