Chap 1 - Measurements And Uncertainties

Question 1

Mention the fundamental units

Answer 1

Metre(m): Length. 
Kilogram(kg): Mass. 
Second(s): Time. 
Ampere(A): Current. 
Kelvin(K): Temperature.
Mole(mol): Amount of substance.
Candela(cd): Luminous intensity (brightness).

Question 2

Describe the difference between fundamental and derived units

Answer 2

Fundamental units describe a fundamental feature about something.
Derived units are derived from the fundamental units. Hence, they connect fundamental units to describe something differently.

Question 3

What does “order of magnitude” mean?

Answer 3

A number rounded to the nearest power of 10.

Question 4

Define systematic error.

Answer 4

An error due to faults in the system (equipment)

Question 5

Define random errors

Answer 5

Caused by human mistakes (estimations and approximations)

Question 6

What is the difference between an accurate and precise measurement?

Answer 6

Accurate values are close to each other. Precise values are close to the expected value.

Question 7

What is absolute and relative uncertainty?

Answer 7

Absolute uncertainty: The range of values the measurement lies between.
Relative uncertainty: Percentage uncertainty (absolute uncertainty/value)

Question 8

How do you add uncertainties when adding or subtracting?

Answer 8

The absolute uncertainty of the two values are added.

Question 9

How do you add uncertainties when you multiply or divide values?

Answer 9

Add the relative(percentage) uncertainties.

Question 10

How do you add the uncertainties when raising a value to a power?

Answer 10

The relative uncertainty multiplied the power.

(4+-0.1 cm)^3 = 64+-0.3 cm^3

Question 11

What is the difference between vector and scalar values?

Answer 11

A scalar value is the size of a value (magnitude). (Speed)

A vector quantity have both a size and direction. (Velocity)