1.5 Analysing Sc Inv

8/8/2019 1.5 Analysing Sc Inv

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1.51.5

Analysing AnalysingScientificScientificInvestigationsInvestigations


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M AKING INFERENCE

Observe situations and identify a question suitable tocarry out an investigation.

: Spring extents more by the heavier baby.heavier

lighter

Extension of the spring depends on the

weight of the baby.

Inference

or


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V ariables

M anipulated variable :

Force / load on the spring

Responding variable :

Extension of the spring

fixed variable :

Force constant of the spring / diameter

of the spring


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H ypothesisThe statement of relationship between themanipulated variable and the responding variable.

H ypothesis :The heavier the weight of load , thelonger the extension of the spring.

0r As the weight of load increases, the

extension of the spring increases.

bigger the force

force on the spring


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Observation and DataTabulation of data :

Weight of load, W / N

Extension of spring,x /cm

0.6

1.3

2

2.4

1.7

3.5

1.02.0

2.5

3.04.0

6.0

2.0


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Analyse data and making conclusion

Interpret data by graphs

0 2 4 6 80

1

2

3

4

W /N

X / cm

A straight linegraph passingthrough origin,

thereforeextension of spring , x, isproportional to the

weight of load, W.

The hypothesis istrue.


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Suatu garis lurus penyuaian terbaikmempunyai ciri berikut:

1. M elalui seberapa banyak titikyang mungkin.

2. Bilangan titik di kedua-dua belahgaris lurus itu adalah hampir

sama banyak.

Garis Lurus Penyuaian Terbaik


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Contoh V (l ) 0.5 1.0 1.5 2.0 2.5 3.0m (kg) 0.35 0.84 1.23 1.60 2.00 2.37

0 1 2 3

0.5

1

1.5

2

2.5

3

m (kg)

V(l )

Best fitline


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Important points to note

Tabulate data

1.First column for manipulated variable.

Second column for the responding variable. Additional columns can be drawn if computation of variables are required.

3. All values in the same column must be

consistent in decimal places.

2. State the correct units respectively .


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Important points to note

Drawing graph

1. M anipulated variable at x-axis. Responding

variable at Y-axis.

4. M inimum size of the graph is 10 cm tall

x 8 cm across.

3. Uniform scale. Do not use odd scale.

2. Label the axes and the correspondingunits for the variables.


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6. State the correct relationship as follow:

5. Draw a smooth best fitted graph.

x

y

0

y is proportional to xx0

y increases linearlywith x

x2

1 /x

y

0

y is inverselyproportional to x

x0

1 /y

x0

y decreases

linearly with x

y

a b

c d


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Practical Exercise pg 7(Prc) A student pours water into a cylinder andmeasures the height of the water at differentvolumes. Figure 1.3 shows the height of thewater in the cylinder at different volumes.

50

100

150

200

250

4.5 cm

50

100

150

200

250

9.1 cm

50

100

150

200

250

13.4 cm 50

100

150

200

250

18.0 cm

50

100

150

200

250

22.6 cm


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Based on the experiment, state(i) The manipulated variable,(ii) The responding variable,(iii) The fixed variable.

(a)

(b) Based on the readings of the height of water, H cm at different volumes, V ml,record the readings in table form.

(c) Plot a graph of H against V, based onthe tabulated data.


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From the graph , explain therelationship between H and V .

(d)

(e) State the precautionary measures whichshould be taken during the experiment.

1.5 Analysing Sc Inv

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