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Scientific Enquiry - Drawing conclusions from experimental results

Grade 4IGCSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

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A conclusion is a summary of what has been learned from an experiment, explaining whether the results support the original prediction.

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Identifying patterns: Scientists look for trends in data, such as 'As variable XX increases, variable YY decreases.'

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Using evidence: A strong conclusion must refer to specific measurements, for example, 'The plant in the sun grew 15 cm15\text{ cm} while the plant in the shade only grew 5 cm5\text{ cm}.'

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Fair Testing: For a conclusion to be valid, only the independent variable should be changed, while all other conditions are kept constant (cc).

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Anomalies: Sometimes data points do not fit the pattern; these are called outliers and should be noted when drawing conclusions.

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Reliability: Repeating an experiment multiple times (n>1n > 1) and calculating a mean (xˉx̄) helps ensure the conclusion is accurate.

📐Formulae

Average (Mean)=Sum of all resultsNumber of trials\text{Average (Mean)} = \frac{\text{Sum of all results}}{\text{Number of trials}}

Change in value=Final Value−Initial Value\text{Change in value} = \text{Final Value} - \text{Initial Value}

Speed(v)=Distance(d)Time(t)\text{Speed} (v) = \frac{\text{Distance} (d)}{\text{Time} (t)}

💡Examples

Problem 1:

A student measures how long it takes for 10 g10\text{ g} of sugar to dissolve in water at different temperatures. At 20∘C20^{\circ}\text{C}, it takes 60 s60\text{ s}. At 40∘C40^{\circ}\text{C}, it takes 30 s30\text{ s}. At 60∘C60^{\circ}\text{C}, it takes 15 s15\text{ s}. What conclusion can be drawn?

Solution:

The higher the temperature of the water (TT), the faster the sugar dissolves (tt decreases).

Explanation:

The data shows a clear pattern where increasing the temperature by 20∘C20^{\circ}\text{C} intervals significantly reduces the time needed for the sugar to dissolve.

Problem 2:

In an experiment testing the strength of magnets, Magnet A lifted 55 paperclips, Magnet B lifted 1212 paperclips, and Magnet C lifted 88 paperclips. Which magnet is the strongest and why?

Solution:

Magnet B is the strongest magnet.

Explanation:

Evidence-based conclusion: Magnet B was able to lift the highest number of paperclips (1212), which is 44 more than Magnet C and 77 more than Magnet A.

Problem 3:

A student predicts that a heavy ball will fall faster than a light ball. After testing, both a 100 g100\text{ g} ball and a 500 g500\text{ g} ball hit the ground at the same time (t=1.2 st = 1.2\text{ s}). What should the conclusion state?

Solution:

The mass (mm) of the ball does not affect the speed at which it falls to the ground.

Explanation:

The conclusion must state that the initial prediction was incorrect because the recorded time (tt) was identical for both masses.