paper 3A practical skills

Question 1

how is the minumun nomber of data points you need

Answer 1

5

Question 2

if a straight line graph is produced what do you need to state

Answer 2

if it passes through the origin or not

Question 3

need to state the range and inteveal of you _______ _______

Answer 3

indipendent veriable

Question 4

depndent veriable

Answer 4

the thing you measuring

Question 5

independent veriable

Answer 5

the thing you changing

Question 6

you need to state how you will _____ the _______

Answer 6

reduce, uncertency

Question 7

concordent

Answer 7

in agreement

Question 8

allways state that you should repeat this measurment untill results are…

Answer 8

concordent and then take the avarge

Question 9

systimatic erorrs reduce…

ramdom erorrs reduce…

Answer 9

accurecy

accurecy and precision

Question 10

what can you do to reduce percentage uncertency when you have a fixed absalute uncertency

what can you do to reduce absalute uncertency

Answer 10

use larger values in the exproment as the absalute uncertency will then be a smaller percentage of the value

use equipment or measuring technecs that have greater resolution

Question 11

what can you do to reduce random errors

Answer 11

• carry out repeats untill concordent results are achieved
• remove anomalies
• calculate mean / avarge

Question 12

how can you detect systematic errors

Answer 12

measure a known value

(you do this when calibrating equipment)

Question 13

when questions ask you to calculat the uncertency which one are they refering to?

Answer 13

absalut uncertencey

(only calculate % uncertency if the question specificaly askes for it)

Question 14

what is the diffrence between a reading and a measurment

what is the absalute uncertency of a reading and of a measurement

Answer 14

a reading is were you only make 1 judgment (e.g taking the reading from a balence)
a measurement is when you make 2 judgments (e.g mesuring a distence with a ruler)

reading is 1/2 x reselution
measurement is 1 x reselution
(as measurement is 1/2 x reselution + 1/2 x reselution)

Question 15

if the experomenter creates more uncertency by carrying out the experoment then the qequipment then what do you do (e.g if reaction time is less then the reselution of a stopwatch)

Answer 15

take the largest uncertency wich would be from the experomenter (e.g the reaction time)

Question 16

what is the uncertency of values given (e.g nomber of lines per meater = 3.5x10^3)

Answer 16

absalute uncertency is +- the last sig fig (e.g 0.1x10^3)

Question 17

how to calculate the absalute uncertency for the mean of repeted values

e.g 5 6 7 8 9 25

Answer 17

find the absalute uncertency:
remove anomilys results
then
range/2

9-5=4
4/2=2
∴5+6+7+8+9 /5 =7
∴answer is 7+-2

Question 18

when:
adding or subtracting data you ____ absalute uncertainties

multiplying or deviding data you _____ percentage uncertenties

rasing data to a power you ______ percentage uncertenties

Answer 18

add

add

multiply

Question 19

how to you find graidinets from straight line graphs

how do you find graidient form curved graphs

Answer 19

draw the largest possible gradient triangle (have to draw the tiangle)

draw a tangent at the point that is wanted and find the gradient of that tangent

Question 20

error bars a graphical representation of…

error bars should be…

when is a reult anomylis

on a graph how do find the absalute uncertency in gradient

Answer 20

absalute uncertency

drawn on all experomental values you take

when teh line of best fit does not pass through any of the values error bars

best line of best fit - worst line of best fit

Question 21

are zero errors

what error is this

Answer 21

when the quipment fails to read 0 when it should do

systematic

Question 22

for point on a graph you must use…

Answer 22

x

Question 23

do you have to stater form 0 on a graph

Answer 23

no you are suposed to only use the part of the graph that is relevent to the data e.g start on the y and x axis a 3

Question 24

if they ask how you can reduce uncertency always think about:

Answer 24

• repeat untill values concordent then take avarge ∴ reducing random errors
• technology (camras, light gates, motion sensers linked to data loger) ∴ reduce human error
• reduce paralax error
• repeat, find anomalies, discard anomalies

Question 25

logs are at least __ sig fig4

Answer 25

4

Question 26

you take the _____ dp when using values (not including logs)

Answer 26

lowest

Question 27

how much time is reaction time

Answer 27

0.1s

Question 28

you can ______ the y and x axis of osciliscopes

Answer 28

adjust