Section Two

Question 0

what is the dependent variable?

Answer 0

the mass the strip carries

Question 1

what is the independent variable?

Answer 1

the five different widths of the plastic strips

Question 2

what are the control variables?

Answer 2

the same plastic bag is used
the length of polymer strips
the amount of mass added each time
the thickness of the strip

Question 3

what is the hypothesis?

Answer 3

the strength of a polymer strip depends on the width of the polymer (plastic) strip.

Question 4

in general what is the independent variable?

Answer 4

what you change

Question 5

in general what is the dependent variable?

Answer 5

what you measure

Question 6

in general what is the control variable?

Answer 6

what you keep the same

Question 7

what is the rhyme to help remember the variables?

Answer 7

…

Question 8

how is the independent variable (the width of the plastic strip) measured?

Answer 8

in millimetres

Question 9

what is the dependent variable (the weight applied before the strip tears) measured in?

Answer 9

newtons - N

Question 10

what is the interval between the independent variable?

Answer 10

10mm

Question 11

explain whether this interval is appropriate:

quote two sets of data to support answer

Answer 11

the interval IS appropriate because:
each width of plastic strip had different results
an increasing weight had to be added/applied and there is a clear trend in the results that supports the hypothesis, for example, 10mm - 25N and 20mm - 50N

Question 12

why do repeats need to be performed?

Answer 12

to check for anomalous results,
to make your results valid,
to see if your results are repeatable.

Question 13

describing whether results support a hypothesis.

state whether the results support the hypothesis
describe the pattern or trend in the results
use two sets of data to support your answer

results:
 width of plastic strip mm - weight applied N
10 - 25
20 - 50
30 - 75
40 - 100
50 - 125

Answer 13

the results do support the hypothesis because each different width of plastic held by a different weight. the wider the strip of plastic the greater the weight before it tore: 10mm tore at 25n and 50mm tore at 125N

Question 14

define reproducible

Answer 14

a measurement is reproducible if the investigation is repeated by another person by using different equipment or techniques and he same results are obtained.

Question 15

why may both two sets of data be reproducible?

Answer 15

because both sets of results are very similar with the same trend. the 10mm strip tore in both sets of results are 25n and 22n.

Question 16

how could the results from your investigation could be useful in the context you researched?

Answer 16

examples of suitable contexts could include the width of polymer supporting the straps for lifting equipment for the minimum width of the polymer strips used a handles of bags.