Uncertainties, Prefixes and Significant Figures

Question 1

pico (p)

Answer 1

x10 -12

Question 2

nano (n)

Answer 2

x10 -9

Question 3

micro (µ)

Answer 3

x10 -6

Question 4

milli (m)

Answer 4

x10 -3

Question 5

kilo (k)

Answer 5

x10 3

Question 6

mega (M)

Answer 6

x10 6

Question 7

giga (G)

Answer 7

x10 9

Question 8

tera (T)

Answer 8

x10 12

Question 9

rule for significant figures

Answer 9

answer should have no more than 2 more or 1 less significant figure than the value in the question with the least significant figures

best to answer with same significant figures as the question

Question 10

how to ensure you get an accurate answer to a calculation

Answer 10

keep everything in your calculator as you go and do not round until the final answer

Question 11

scale reading uncertainty in a digital scale

Answer 11

+/- 1 of the smallest division

Question 12

scale reading uncertainty in an analogue scale

Answer 12

+/- 0.5 of the smallest division

Question 13

what is an absolute uncertainity?

Answer 13

written as a value, not a percentage

Question 14

how to work out % uncertainity

Answer 14

uncertainty/value x100

Question 15

what percentage uncertainty should be used when calculating the uncertainty for an unknown variable

Answer 15

the highest % uncertainty in the known values

Question 16

how to work out absolute uncertainty from percentage

Answer 16

simply multiply value by % (use % button on calculator)

eg: 31 x 4.8% = 1.5

Question 17

when do random uncertainties come about

Answer 17

when we make repeated measurements of the same thing

Question 18

equation for random uncertainty

Answer 18

Rand = max-min / n

Question 19

how to make random uncertainty smaller

Answer 19

take more readings

dividing by a larger number

Question 20

why do systematic uncertainties happen?

Answer 20

problems with the set up of the experiment

eg: a meter not calibrated correctly

Question 21

graph of experiment with systematic uncertainty

Answer 21

straight line but does not go through origin