2 - Foundations of physics

Question 1

What are SI units

Answer 1

Fundamental (base) units of phyiscal quantities

Question 2

What are the SI units of mass

Answer 2

kg

Question 3

What physical quantity is measured in mol?

Answer 3

Amount of substance

Question 4

What is the SI unit of current?

Answer 4

Amperes

A

Question 5

Is the SI unit for temperature °C or K

Answer 5

K (kelvin) as this is the absolute scale

Question 6

What is the SI unit of length?

Answer 6

Metres - m

Question 7

What quantity is measured in seconds?

Answer 7

Time

Question 8

Are newtons an SI unit

Answer 8

No, newtons are not fundamental, the SI units for force are kgms^-2 (since F=ma)

Question 9

Derive the. SI units for energy

Answer 9

E=1/2mv^2

units = kg m^s s^-2

Question 10

Derive the SI units of force

Answer 10

Force = mass x acceleration
Units = Kgms^-2

Question 11

Express 60 T Ω in standard form

Answer 11

60 x 10^12

Question 12

Write 0.000003m with a suitable prefix

Answer 12

3μm (3x10^-6m)

Question 13

What is accuracy?

Answer 13

Accuracy is a measure of how close a measured value is to the true accepted value

Question 14

What is validity?

Answer 14

A measurement is valid if it measures what it is supposed to be measuring. An experimental procedure is valid if the obtained values provide an answer to the question that is being asked

Question 15

What is random error

Answer 15

An error that occurs due to unexpected changes during an experiment> These cannot be predicted and they can cause repeated results to differ from one to another

Question 16

What is an anomaly?

Answer 16

An anomaly (also know as an outlier) is a data point or value in a set of results that does not fit the trend of the data and is therefore an unexpected result. These can happen as a result of random errors during an experiment

Question 17

What is a systematic error?

Answer 17

An error that occurs due to faults in equipment or equipmental method. Systematic errors cause the result to differ by the same amount each time, making them predictable. They can occur due to not callibrating an instrument correctly

Question 18

What is precision?

Answer 18

How consistent/close together repeat readings are - the closer they are, the more precise they are

Question 19

What is meant by resolution?

Answer 19

The smallest change in the quantity being measured that gives a recognisable change in reading
e.g on a ruler the resolution is 1mm

Question 20

What is absolute uncertainty?

Answer 20

Uncertainty given as a fixed quantity

Question 21

What is an order of magnitude

Answer 21

Powers of ten which describe the size of an object and which can also be used to compare the sizes of objects

Question 22

What is meant by a scalar quantity?

Answer 22

A quantity that only has magnitude

Question 23

What is a vector quantity?

Answer 23

A quantity that has magnitude as well as direction