Units & measurement
7 independent quantities:
length(m), mass (kg), time(s) Temp.(K), urrent(A), Luminous intensity (ld), ami of subs. (mol)
plane angle do = ds radians
• Solid angle D d2 = dA 2
solidangre for full supere = D
I light year=9.4.6 X1015 1
1 parsec: 3.28 light yr.
ime: caesium atomic clock.
errors
Systematic Cintroduced due to inaccuracy) instrumental exp technieve Personal error
sandom
(due rovariction inconditions in which exp occurs)
mean absolute error. Samean(la-al)
value of 'a lies blo a = Amean ± amean
relative ermor = Damean amean
Z=A+B
A2=IAA + AB
Z=AB A +43 B A
6 B trac C
A X10