2- Foundations of Physics

Question 1

What are quantities?

Answer 1

Properties of an object / substance / phenomenon that can be measured or calculated. Quantities can be variables or constants. Most have units, some do not

Question 2

State the seven SI units. What are they?

Answer 2

An internationally recognised system of units of measurement.
Defines seven base units for 7 variables
The units for every other variable and constant can be derived from these seven units.

metre - Length
kilogram - Mass
second - Time
amperes - Current
kelvin - Temperature
mole - Amount of substance
candela - Luminosity

Question 3

What are the prefixes of units and their factor?

Answer 3

peta, P, 10^15
tera, T, 10^12
giga, G, 10^9
mega, M, 10^6
kilo, k, 10^3

deci, d, 10^-1
centi, c, 10^-2
milli, m, 10^-3
micro, u, 10^-6
nano, n, 10^-9
pico, p, 10^-12
femto, f, 10^-15

Question 4

Define physical quantities

Answer 4

Physical quantities have numerical value and a unit