1. Fundamental & Derived Units
IB expects you to know them

2. 7 Base/Fundamental Units
Unit Symbol Dimension
Meter m length definition
Kilogram ___ ______ amt matter.
Second ___ ______ __________.
Ampere ___ ______ __________.
Kelvin K ______ __________.
Mole mol ___________________.
Candela cd intensity of light.

3. Derived Units: Combos of base
Mechanics – motion, force, matter. All units derived from kg, m, s.
Ex: density, velocity.

4. Remind yourselves of the metric prefixes
Remind yourselves of the metric prefixes. See Hamper pg 6 and Data booklet.

5. Ex: How may cm3 in 4 m3?
4 x 106 cm3.

6. 1. What are the base units of Joules?
kg m2 s-2.

7. 2. What unit is a C/s?
Ampere

8. 3. What quantity is represented by the base unit below?
kg m2
s3 A
Volts

9. Order of Magnitude & Estimation
Physics must explain the very large & the very small.
A number rounded to the nearest power of 10 is called its order of magnitude.

10. 4: A human high school student was estimated to weigh 300-N on a planet whose g = 0.1 m/s2. Show why that is NOT a reasonable estimation.
Fg = mg so
300-N/0.1 m/s2 =
3000 kg.
Students are ~ kg.

11. 5. The universe ~10 25 m across. It is ~ 15 BY old.
How many seconds is that?
~ seconds

12. 6. Diameter: Atom ~ 10 – 10 m Nucleus ~ 10 – 15 m What is the ratio between the two?
10 5.

13. 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.

14. 7. What is the order of magnitude of 200 nm in meters?
10 -7

15. Hwk: Kerr pg 1-4. do pg 2 #3-5 and pg 3 #1, 2, 4.
Write your whole name.
Date.
Assignment.
Label questions.
Show work.

16. Activity Order of Mag Estimation
Fermi Estimations 4 min
Activity Order of Mag Estimation