Science section B is the most difficult part in Science paper.
You need
to complete the section B within 30min. It carries 20 marks. In order to
answer the section B well, you need to understand the pattern of the question and the
keywords.
Here are thel keywords that you need to understand in section :
-constant variables (variables that are kept the same), responding variable, manipulated variables
(changed), aim (purpose), hypothesis (relationship), inference (reason) and
conclusion.
Let us look at the differences between constant variable, responding
variable and manipulated variable.
Constant variable, Responding variable, Manipulated variable
Constant variable: Does not change or varying. Sometimes they will use the
term as 'kept constant'
Responding variable: To act in return or in response to an external factor or
the stimulation.
Manipulated variable: Controls individual factor causes. Another term
used is 'changed'
Mnemonic Graph & Table analysis
When come to data analyzing, here are some mnemonics that can help you to
figure out the
responding variable and manipulated variable from graphs and tables:
- Left Change Right Respond
- Up Change Down Respond
- Horizontal Change Vertical Respond
and remember that Unchanged is constant , to look for constant variable.
Left Change Right Respond
Diagram 1 shows an investigation of frictional force. Table 1 shows the
result of the investigation.
Refering to table 1, the data on the left shows the types of surface to use in
the investigation. It is controlled by the investigator and will affect the end
results of the investigation. Thus, surface is
manipulated (changed) variable .
The data on the right shows the distance travelled by a toy car. The changes
is due to the surface used. Thus, the end results on the right column is depend
on (respond to) the changes on left. Distance travelled by a
toy car is responding variable.
What is the unchanged data? The height of the surface and the toy car.
The student will use the same toy car and same height of the surface for every
test. So, toy car and height are
constant variables.
Up Change Down Respond
It means the data on the upper part of the table is manipulated (changed) variable. The data at the bottom
part of the table
is responding variable.
(Table 2)
Ah Beng prepared 2 beakers which are filled with 300ml water. The water
temperature used is 40Cº and 100Cº respectively. Ah Beng adds in 8 table spoons
of sugar into each beaker and stirs until the sugar is fully dissolved. Table 2 shows the result of an investigation about the
time taken to dissolve the sugar.
In this investigation, the water temperature is
manipulated variable, because changes in the water temperature will affect the end result of the time taken
for sugar to dissolve in water.
The data at the bottom (Time taken for sugar to dissolve)
responds to the manipulated variables. The result depends on the
temperature of the water.
Constant variable are beakers and
water volume, because both tests are using the same bealer size and the same
amount volume of water.
Horizontal Change Vertical Respond
The data on horizontal axis is manipulated (changed) variable.
The data on the vertical axis is responding variable.
(Diagram 2)
Diagram 2 shows a bar chart on the number of telephone numbers memorised by 5 people
aged 25, 35, 45, 55 and 65 years.
In this investigation, the age is the
manipulated variable. As the age changes, the number of telephone
numbers could be memorised changes. The number of telephone
numbers that can be memorised is responding variable.
The result depends on the age of the person.
Constant variables are the numbers of telephone number and
the time given to memorise the telephone numbers used in the
investigation must be the same.
Great help.
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