PAPER 2
SECTION B
1.Diagram 1 shows the apparatus set up to study the effects of temperature on bacterial growth.
Diagram 1
Table below shows the results of the experiment recorded after 48 hours.
a. State the variables involved in this experiment.
i. Manipulated variable: _________________________________
ii. Responding variable: __________________________________
iii. Constant variable: __________________________________
b. State the inferences for the results of the test tube X.
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c. Based on the experiment state one way to prevent the growth of bacteria.
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d. What is the conclusion from this experiment?
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2. Diagram 2 shows the experiment carried out by a student.
Diagram 2
a. What is the aim of this experiment?
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b. State the variables in the experiment:
i. Manipulated variables: ____________________________________
ii. Responding variables: _____________________________________
c. Why are the test tubes covered with black paper?
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d. What is the function of test tube U?
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3. Diagram 3 the apparatus set up to prepare soap in the laboratory.
Diagram 3
a. What is the process called in the preparation of soap?
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b. What is X?
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c. Why substance Y is added to the mixture of soap and glycerol?
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d. State one characteristic of the soap?
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e. Write a word equation for the preparation of the soap.
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4. Diagram 4 shows two cans hung with long strings onto horizontal pole. Can P is filled with sand while
can Q is empty.
Diagram 4
a. Which can will stop first when it is move?
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b. Give your inference for your answer.
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c. State the relationship between mass and inertia.
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d. Give one example of application in everyday life based on the relationship state in (c).
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5. An experiment was carried out to analyse the motion of a trolley moving down a smooth inclined
slope. The apparatus used in the experiment were arranged in diagram 5.
Diagram 5
A section of the ticker tape obtained in the experiment is shown in the figure below.
a. What is the average initial velocity of the trolley?
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b. What is the final velocity of velocity?
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c. Determine the acceleration of the trolley.
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d. What is the average velocity of the trolley?
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6. A student carried out an experiment to compare natural rubber with synthetic rubber. Figure 6 shows
the set-up of the apparatus for the experiment. A strand of natural rubber is stretched by a load of 100g
and the extension of the strand is determined by measuring the lengths of the
strand before and after it is stretched.
The experiment is repeatedly by replacing the strand of natural rubber with
a strand of synthetic rubber of the same dimensions.
Figure 6
a. State the responding variable in this experiment.
______________________________________________________
b. State the manipulated variable in this experiment.
______________________________________________________
c. State the fixed variable in this experiment
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Table above shows the results obtained by a student.
d. What conclusion can be made from the experiment?
______________________________________________________
e. Explain why the characteristic of synthetic rubber investigated in the experiment differs from that of
natural rubber.
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7. An experiment was carried out to investigate the relationship between pressure, force and surface
area. The experiment was set up as shown in figure 7.
Figure 7
An experiment was carried out block if mass 5.0kg and dimensions 4 cm x 6cm x 12 cm is placed on a
layer of sand in a trough. Each face of the block is placed in turn , on the sand and the depression of the
block in the sand is recorded.
a. Suggest a suitable hypothesis for the experiment.
____________________________________________________________
b. State the variables:
i. Manipulated variable: ________________________________
ii. Responding variable: ________________________________
Table below shows the result obtained from the student.
c. What is the relationship between the surface area and the pressure?
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d. What is the operational definition for the pressure?
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ANSWERS
1. a. i. temperature, ii. the growth of bacteria, iii. Quantity of nutrient broth/type of bacteria.
b. the nutrient broth is cloudy because the bacteria are active/growth
c. keep in the freezer/boil at high temperature.
d. the suitable temperature for the growth is room temperature
2 a. to study the requirement of the plants
b. i. type of culture solution ii. the growth seeding
c. to prevent the sun light from support the growth of algae
d. controlled experiment
3 a. saponification
b. sodium hydroxide/alkaline solution
c. to make the soap float
d. greasy
4 a. P
b. P stop quickly because P have large mass.
c. the mass increase the inertia increase
d. A heavy lorry take time to stop./relevant example
6. a. extension of the strand
b. material of rod
c. mass of the load
d. natural rubber can be stretch more than synthetic rubber
e. the presence of ink in synthetic rubber make it less streactable.
7. a. the smaller the surface area the larger the pressure.
b. the surface are the depression in the sand
c. surface area increase the pressure decrease
d. the operational definition for pressure is shown by the depression of the metal block.