1. Physical quantities and units

Question 1

Physical quantities

Answer 1

all physical quantities consist of a numerical magnitude and a unit

Question 2

Estimating Physical Quantities

Question 3

SI base quantities and units. What are derived units
what is homogeneity

Answer 3

mass (kg), length (m), time (s), current (A), temperature (K)

derived units are products or quotients of the SI base unit

where each term has the same base unit, it is balance and hence homogeneous

Question 4

prefixes and their symbols to indicate decimal submultiples or multiples of both base and derived units:

Answer 4

pico (p)- 10^-12,
nano (n)- 10^ -9,
micro (μ)- 10^-6,
milli (m) 10^-3,
centi (c)- 10^-2,
deci (d)- 10^-1,
kilo (k)- 10^3,
mega (M)- 10^6,
giga (G)- 10^9,
tera (T)- 10^12

Question 5

explain the effects of systematic errors (including zero errors) and random errors in measurements

Answer 5

Systematic-

Random-

Question 5

distinction between precision and accuracy

Question 6

understand the difference between scalar and vector quantities and give examples of scalar and vector quantities included in the syllabus

Question 7

assess the uncertainty in a derived quantity by simple addition of absolute or percentage uncertainties