Fundamental Derived Units 7 BaseFundamental Units Unit Meter
Fundamental & Derived Units
7 Base/Fundamental Units • • Unit Meter Kilogram Second Ampere Kelvin Mole Candela Symbol Dimension m length definition ______ amt matter. ___ __________. K __________. mol __________. cd intensity of light.
Derived Units: Combos of base • Mechanics – motion, force, matter. All units derived from kg, m, s. • Ex: density, velocity.
Remind yourselves of the metric prefixes. See Hamper pg 6.
1. What are the base units of Joules? kg m 2 s-2.
2. What unit is a C/s? • Ampere
3. What quantity is represented by the base unit below? kg m 2 s 3 A Volts
4. Break down the unit W (ohm) into base units. • kg m 2 s-3 A-2.
Order of Magnitude & Estimation • Physics must explain the very large & the very small.
The universe ~10 25 m across. It is ~ 15 BY old. • How many seconds is that? ~ 10 18 seconds
The power of 10 is order of magnitude. • Useful for estimation of the very large & very small.
Diameter: Atom ~ 10 – 10 m Nucleus ~ 10 – 15 m What is the ratio between the two? 10 5.
Wavelength of light few hundred nm (400 – 700) Frequency light ~ 4 – 8 x 1014 hz. • Try to memorize the previous quantities. • See list on pg 1 in Kerr.
Hwk: Read Hamper 1 – 6. Do pg 3 - 6 # 1 – 7 Show work or write word. • • • Write your whole name. Date. Assignment. Label questions. Show work.
Make estimations in groups outside.
Do Now: How may cm 3 in 4 m 3?
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- Slides: 17
