Natural Sciences and Technology Grade 5-B ... - Thunderbolt Kids

2. What is needed for combustion to take place?
heat, fuel and oxygen
3. Your dad is cooking with hot oil on the stove. The oil catches
fire. Suggest a way to put out the fire and explain why it will
work.
Put the lid on the pot. This will cut o the oxygen needed to
burn and the fire will go out. Do not use water to put out an
oil fire.
4. An enthusiastic Science learner decides to perform an
experiment to find out how long dierent quantities of
firelighters will last. Each firelighter was cut into equal size
blocks. The experiment was performed under adult
supervision, and the following results were obtained:
Number of firelighters Time of burn (min)
2 6,0
4 11,5
6 18,6
8 23,8
12 37,0
16 48,0
a. Plot agraph of number of firelighters on the horizontal (x)
axis and the time of burn on the vertical (y) axis.
b. Draw a line of best fit on your graph.
Teacher's Note
Line must NOT join the points. Must be aline drawn with a
ruler that is as close to the data points as possible. There
should be as many data points above the line as below.
Chapter 1. Stored energy in fuels
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